She didn’t tell you that her job is a priority because it’s not something to tell. It’s kind of a given that once a week class cannot take a priority over a full time job that pays bills. It’s silly she says “I told you”. She didn’t but she possibly thought she did as it’s common sense

At this point I think it’s clear she’s not into very deep friendship, she is ok with occasional hanging out and chats and she has no time or interest for teaching this art class. Now it’s your turn to decide on your course of action