Will my girlfriend cheat?

Okay so my girlfriend used to go up to randoms boys and kiss them at school but this is before i knew her and she used to go to partys and she used to twerk(rub her *** on boys) at football game and stupid ****.. and i always find **** out and she said she dident remember but i asked her friend i was acting like my GF and i asked her friend if i ever told her about a boy other than justin and she said that tall boy you told me about and u was talkin bout me not going to the mall... So i just wanna know about this Tall boy but she swears she dont know what she talking about... Mane i just need some help bra i dunno if she will do it to me... im also worried because she has a webcam and she used to call every boy on there and i wonder if she showed any of them her titties... and when i asked her to show her **** to me when i first met her she did it and she went with someone... But she is schizoaffective if that matters... But please tell me... do u think she has cheated or will cheat?