Girl likes me and is open to FWB, but she doesn’t want a serious relationship. How do I approach this relationship.

So I’ve gotten close with a an old classmate of my mine (I went to boarding school with her). I really enjoy spending time and talking to her but she’s let me know kindly that she isn’t wanting a serious, established relationship. So far we’ve met 3 times and we’ve kissed, cuddled, had good talks and she’s let me know sex is something she’d like. My question is with all this information should I/Do I need to change how I approach this relationship or do just let it happen? Sorry for the long rant but I’m a guy whose IQ drops to 10 around girls I like