AITA for accusing my coworker friend of lying to me?

I (31M) asked my coworker friend (33F) if she was interested in being my field instructor for my internship. Body language was disinterested, she deferred the responsibility on another coworker and she tried telling me how boring her job is. That I would be better off interning elsewhere. She works in another department than me. I asked if this was something she really wanted to do and she agreed she did so I took her word for it. She agreed to ask her supervisor for approval asap because I had a deadline approaching. I’ve had trouble finding field instructors for sometime now.

Fast forward two weeks, I hear nothing. I have a run in with her supervisor and find out he knew nothing at all about any of it. I worked with her again and told her I felt lied to and let down. She said she completely forgot, has been busy at work and hasn’t seen the supervisor lately. She took accountability for forgetting and apologized, but given everything I mentioned earlier, my gut was telling me there was more to the story. I asked if I did something to upset her which she said no. We never yelled or talked down to each other during this conflict, but I said I didn’t believe her. We didn’t talk for the rest of the shift.

I tried calling her the next day to apologize for jumping to conclusion with no answer. I tried texting an apology but she was very dismissive and avoidant. I let her know that the messages she’s now sending, I’m hearing them loud and clear and that it’s been real being friends. Not a good move on my end. What makes this more complicated is that her supervisor is now going to be my field instructor, so I will be seeing her a lot more now.

I really wish I had been more calm, not jumped to conclusions and followed up in between those two weeks but her story just didn’t make sense to me. She’s very intelligent, collected and organized so I can’t believe she would just forget about me unless she either lied or just didn’t care.