Most Helpful Girl
she probably does.
Most Helpful Guy
Do you trust your girlfriend? has she given you any reason not to trust her? Does her actions seem doubtful to you? body language?
It's not necessary that just because her friends are cheating on their boyfriend that she will also cheat on you, however, I must say she is not having a good friend circle, but there is a possibility of that happening, just a possibility so just be alert be careful. Don't stress about it.