What to say to people who bash you for having sex often

My boyfriend and I have sex everytime we see each other which is about 3 times a week and we have been dating for 7 months. And my cousin comes to me for sex advice and I give her details and tips from my personal experience however at time she would bash me by saying “you did it too early” “all she likes to do is have sex” and one time when I had really bad cramps she said “be grateful at least you are not pregnant”. I don’t regret having sex early but it does bother me that she thinks she has a say in my sexual life and I have talked about it to her saying it bothers and hurts me but she still hasn’t stopped. What can I do at this point.