Should I get my chair a card/small going away gift although she has never been there for me? I'm a first year Master's student that works under the supervision of my thesis chair. At first, I was really excited to work with my chair because she is known as one of the nicest people &amp; best profs in the department. However as time went on, those rose colored glasses have come off and I have seen her for who she truly is. 

While I by no means dislike the woman, I have felt extremely dissatisfied working with her as she has canceled countless meetings, made empty promises, and never follows through. She told me she'd help me with my speech for my very first poster presentation but never did. She told me she'd help me set up my poster and be there for me, but never showed up until right before I was about to start presenting. She promises me thesis edits will be made within a certain time frame but always falls through with no email to explain. 

My thesis is a branch off a multi site grant study and I've had to be in personal contact with the head of the grant because she has not been present although the head of the grant is also relying on her. I've done all the preparations for the data collection although she could have definitely helped if she wanted to. 

Because there's been a lull in my recruitment; instead of focusing on that, she's trying to get me to do her dirty work for a former project that has nothing to do with me. Although her former thesis student has already graduated and been accepted to a PhD program, she'll still prioritize that student over me by helping that student publish her thesis.

She's not transparent at all and never gives me her opinion (even on things that do matter), so I often feel alone in making decisions. She also doesn't know how to talk to people. Just last week, out of the blue, she told me she is moving to another state for another job offer in about 2 months but has made no real attempt to help me decide how to deal with my thesis... it's all non novel ideas (like start over) lip service disguised as help. I guess my point is--despite my dissatisfaction, she has NO clue I feel this way and would be quite surprised if she ever found out. 

I'm wondering if I should fake it long enough and even get her a card/buy her going away lunch to ask her for a recommendation letter before she leaves? 

I know it sounds conniving and that's normally not like me, but I am very frustrated with her and feel like that's the least she could do for me, considering she's screwed me over multiple times already in the 4 short months we've been working together. I could really use one from her since I've worked for her the longest so far, and people are telling me that's what I should do.
I understand your frustration but let me explain a supervisor’s point of view. It is your research, your examination, not mine and you are probably doing fine! I would break in only if I would detect problems. 

My university, officially gives me 10 hours for supervising a master thesis student. I have 5 master thesis students under my supervision, I teach, I have piles of examination work, I have students approaching me with all kinds of request (assisting in finding internships). The other part is my own PhD research, publishing and reviewing. All part-time. I also have a regular and demanding job outside the university.

Your supervisor is just extremely busy. I agree with you that your supervisor should follow-up promises or not raise expectations. I suspect her intentions are well meant but reallity and work pressure catch up with her. 

My advise would be to have an open conversation with her to share your disappointment. But also be open for getting feedback because everybody has blind spots. The ideal supervisor doesn’t exist, the ideal student neither. If it still doesn’t work out between the two of you, you could consider changing supervisors.  

Good luck with your thesis. I am convinced you will be graduated in a few months ;-)