Hi a question please I mean how can you tell if someone feels guilty

hi a question please I mean how can you tell if someone feels guilty about something she did, actually I am girl the one who crush on me is girl few days back I have met some girl in party with friends she act so rude towards me and I didnt know why she just did latter on I stayed quiet she tried to excuss me again and I start insulted on her mom then things went up now days I see her she feel guilty I dunno I guess she trying to talk to me no idea because she the first who cross the limit and I did the same towards her one of us two felt guilty no idea but I have feelings she feel nervous when im around and she start making me jealous while having conversation with her friends flirting them but im staying quiet all the way the problem she like me or hate me no idea I really want your advices thanks alot and regards :) and sorry moi anglais de probleme if it does make sense

You can tell someone is guilty if they avoid your eye contact or if they stutter when they usually do not also if they have a constant need to talk about what they are guilty about and yet cant seem to say they are guilty.