And why exactly did you let it happen?

Congratulations. You spoiled your child. And if you keep allowing it - it will only get worse. So you can complain, do something about it or both!

This needs more context. Is the older child special needs or something?

You need to retrieve your authority in your own home!

Well, the only thing worse than letting it go on for 14 years, is letting it go on for 14 years and a day. Time to discipline your kid and reclaim your authority as a parent...not to mention your dignity.

Sorry but YDI for allowing your child to walk over you like a doormat. At the end of the day you’re the parent.

You let her take over, up to you to (metaphorically) slap her back down into place or do you need to Google the concept of 'parenting' your own child? If she turns violent, well that's what CPS is for. Not just protecting kids from adults but adults and siblings from the other kids. If she's got issues they can help you find help, diagnosis and resources. It's either you are a problem parent or she is a problem child, figure that out and you'll be able to find the way forward.

And that's what's wrong with the world today, and parents in general. You're the parent. Act like it. There's no excuse for this.