Mom?

I assume another child dared or prompted daughter to do that and daughter probably didn’t even know what the word actually meant. While it’s embarrassing, no real harm has been done. The bigger concern is that daughter was obviously manipulated by a “dare” or “challenge”. Lots of people buckle under peer pressure to do or say things that are not in their best interest. It probably means, like most children (and most humans in general), she needs or wants affirmation and is easily manipulated, probably by a “friend” to do things that she thinks will get her liked and admired. (1) Explain to daughter that syphilis is a disease. Show her some pictures of what it’s symptoms look like - I can just about guarantee that if you do that she won’t make that claim again any time soon. And at the appropriate time explain about STD’s and how you catch them and what they can do to you. (2) Explain to daughter in age appropriate terms the concept of peer pressure and the dangers in that. Explain that the people who manipulate others usually have no real liking or respect for the people they manipulate. Explain that a brave person does not prove they are brave by doing what their friends tell them to do. A “dare” or “challenge” is one of the stupidest things you could do. Only a coward is swayed by being called “chicken”. Remember that and don’t let your daughter see you be swayed and manipulated that way.

An older kid probably dared her to do it at recess or tricked her into thinking it meant something else. Kids will punk each other, it's normal. That, or you should check what your relatives are teaching her when they babysit...