How should i go about this

For a little bit of context me 15m and 15f (leah) have been talking for like a year. I really like her, she is easy to be around, we have the same hobbies, she makes me Happy and overall just a nice person to have in my life. A few months ago her friends started to tell me that she likes me and that she wants me to ask her. The problem is that im scared of her history. Leahs had 5 boyfriends in her life and ive had one real girlfriend before. I dont know if Thats anything to care about but my friends been telling me that it’s pretty weird and that it’s a red flag. I could probably list Overall 100 things Thats great about her but im still kind of scared just trying to be with her and what that would mean. Like am i just going to be another boy she dates for a month then moves on and leaves me heartbroken. Kinda came here for some advice for what i should do or something like that