Mom is worried the sleepovers I have with friends are making me reckless. Maybe we do things and theres no lack talk of sex. Ok at 15?

Of course. If you were not discussing sexual issues with your friends at this age it would be very unusual. The only word of caution is that you do not believe everything you hear, and take rumors about your friends activities with a grain of salt. Better to get formal sex education. The united church of christ and unitarian universalist church, and perhaps some others, offer excellent courses.