Make a post of your own announcing the baby's gender and saying that if they heard the baby's gender from anyone else, they violated your privacy and trust by going behind your back to do so.Also, cut her out of the loop as much as possible, and I'd keep an eye out for other actions like this or if she tries to guilt trip you about being mad. Based of just this information, she still sounds like a possible case of Narcissistic Personality Disorder. I suggest reading about it and making your o

OWn call, because Narcissists aren't good for kids to grow up around and can even be actively dangerous. Most people that are "attention seeking" have the predisposition for behavior that is dangerous to themselves and everyone around them.

That's actually a really good idea. My response slightly childish but yours is mature and probably effective :)

While I agree with most of your post, please don't self diagnose people with a serious personality disorder that they may or may not have. Personality disorders are serious business. You can be an attention seeking narcissist without it being tied to a disorder.

Oh God. As someone that studies clinical psych I can tell you that throwing around a personality disorder so casually is a real problem and can be stigmatizing to that person. With the said information we can't diagnose someone with NPD.. nor does it sound like NPD.

there is actually a disorder with narcissism in the title I think. There are a lot of personality disorders. Not all are super serious. And it's good always good to consider it so maybe the family member or whomever could actually seek help and having a diagnosis would assist in insurance paying for said help (I'd think..).To deny the fact sonething just might be a psychological disorder, if enough boxes are ticked, would just mean yet another person adding stigma to mental health disorders. They don't have to be the end of world. With management, sufferers can be completely or at leastly mostly "normal".

Five symptoms from this FML alone, unless the SIL did some major apologizing and groveling:
Requiring constant admiration
Having a sense of entitlement
Expecting unquestioning compliance with your expectations
Having an inability or unwillingness to recognize the needs and feelings of others
Behaving in an arrogant or haughty manner

Also, narcissism IS inherently bad. It isn't just arrogance or confidence.

My mother-in-law did the exact same thing. Except there was no Facebook at that time. We didn't want to know the sex but she somehow found out and told everyone with a set of ears. The next day we started getting phone calls congratulating us on the impending birth of our daughter. When we confronted her she said. "I hope you don't mind." Needless to say it was the last time she was given any information.

As a sister in law I'm astonished by this womans awful behavior!! When my brother and his wife had their baby I was super excited myself - but I waited until they had announced everything themselves and asked for permission to share the news afterward. I'm sorry she was so rude and ruined your news, you need to call her on it otherwise this behavior will only continue. Please still go through with the announcement you had planned, after all this is YOUR baby!

Congratulations on having a baby at least!!!

I hope you're not going to jail after you killed your sister from all the anger.

No jokes. I'd be fuming!! And not pregnant woman hormone fuming!

Sorry OP :(. Your sister in law is a heartless bitch. Ps. It's your baby, not hers or "ours". What nerve.

What a bitch, I would cut her out of all the pregnancy activities until the babies are born.

I'm sure the courts would totally see this as justifiable homicide! Personally, I would have been so pissed off that Satan himself would be like "nope, that bitch is crazy pissed off and is scaring me a bit..." I hope you cut her out of your life as much as possible because if she'll do this, who knows what other moments she'll try to steal later in your child's life!

I don't understand how this happens. If you didn't want her there, tell her to fuck off. I mean, if you're pregnant I doubt you rely on her to support you so if you want her gone just say so.

Maybe OP did want the sister in law there because no one else was available to go. However, OP most certainly didn't want that bitch of a sister in law going and telling everyone the news. Seriously OP she is a bitch and you need to distance yourself from her.

Congratulations! Hope you have a healthy and intelligent kid. Don't let the SIL get to you. There will be plenty of opportunities to get even/ she is family/ be the bigger person here.

Wait... "Get even". "And be the bigger person". These are contradictions, Which are you suggesting?

Gender announcement?
Is this a joke or is it really a cultural thing/tradition of your country?

I'd really like to know because where I am from we get to know the gender this way:
1. NO WAY
(Because the parents want to surprise everyone -sometimes even themselves- after birth.
And sometimes they just don't want to hear "Oh, just a boy/girl...I was hoping for *other gender*)

2. THEY JUST TELL
(If you ask, they tell you what they are having.Sometimes they tell you "Hey, last examination made sure we'll have a boy/girl" if they love to tell things from their pregnancy.

That's it.
Not really an announcement, so I'd love to hear what kind of thing you were planning.

And of course I agree with the other posters:
No-one should tell private things right out of the doctor's office without asking if you want them to.
Plainly rude!
Always remember this day if you're sis in law might have something "intimate" she'd love to keep to herself...
(Come on, it was a dick move and you don’t need to be the "greater/better person".
REVENGE!)

Some people have announcement parties, for instance you bake a cake, you put icing depending on the sex (for instance blue of a boy and red for a girll). So when people eat the cake they know whether it's a boy or a girl. I'd say it's trend more than a cultural thing.

You've heard of baby showers, right? A party before the birth of a child to celebrate with the parents-to-be? Most people "announce" the gender the same way. It's just a bit of news that people who care about the new family might want to know. Sometimes it's a party (instead of or combined with a baby shower). Sometimes it's just a "cute" letter/video/vine/email letting people know. Some people go over the top with it, but some people lose their minds about EVERYTHING when they're pregnant and turn it into 9 months of self-congratulations.

Oh, thank you!
I have to admit this sounds nice (I thought announcement meant something very formal).
Ok, you had me by mentioning cake :-)
Perhaps it will get popular here, too.

I never heard of baby showers before...now I googled it and the pics seem quite frightening :-D
(Games with eating baby food...*tremble*)

Ok, now I learned 2 things!

Perhaps it is that celebrating before birth is considered bad luck here but here you just get small presents after birth.
Sometimes (more in the country side) there is a biiiiig party after birth (Babypinkeln= baby peepee/ baby piss) where mostly men drink A LOT!

It's really funny how things differ around the world.
(And I have to admit I was quite happy not to call much attention to my pregnancy and nearly was too tired for the birth annoncement cards - some people send fabulous things, and we just sent a picture with name/date--- not much of an eye catcher...)