Ladies Answer Honestly 10 Points?

Gf of 4 months & i were to hang out Last night. She said “if i get out early from my job i em going to notify you and we are going to hang out i want to get into some reckless ”. Usually she gets out 11pm or later & exactly at 9pm i thought she was still working and out of the cuts i get a pic txt of her in a thong inside her room (she’s clearly going out somewhere she was getting ready) and i txt back saying wow when did you take that and she said “30 min ago” & that was the last txt she sent me i the txt back AGAIN at 12am asking where she was at and she didn’t txt back.
Clearly we were supposed to hang out and never told me she got out early!, but instead she’s out with her girls partying and this isn’t the 1st time she lags on me we only see e/o about every other week & i’m tired of this bs we both said we love e/o but idk what to do we already talked it over and over and she keeps doing herself with her friends all the time!.
What do you honestly think is going on?
*She’s not seeing someone else 100% sure she did say she’s not ready for something serious since her ex was abusive and took her away from the world*
She is 17 & me 19