boundaries are the healthiest and usually they are the hardest. especially if the "boundary needer" is a manipulator/liar/rude/selfish/self absorbed/thoughtless person. i'm not calling your stepmom all of that. it's just the truth. they just don't see boundaries are being necessary to anyone but them. and you've probably noticed that she has boundaries.
expectations just set us up to be disappointed and hurt. i used to have them about my mother. when i was elected to the Planned Parenthood board in Oklahoma City, she was disdainful. (i love using weird words) when i went to work for Willie Nelson, she was scornful. when i started photographing Indian rodeo, she was aghast that i was running around with Indians. ( I AM PART INDIAN..WHERE WAS THAT COMING FROM?) i just always knew that i'd find that magic thing that she would cheer about........never happened. and i expected so little from her. just some respect and recognition for my hard work. she later asked me for Will's autograph and i refused to get it for her.

she also asked me for one of my biggest rodeo photos and i refused that also. she later told my sister that she didn't deserve either request.
i had two MILs who delighted in treating me the way your stepmom treats you. but i didn't have the investment in them that you have in your stepmom. i cut bait on both of them.........but your deal is different. she is your stepmom and validation of you as a human bean would be nice. love, pat