Hmmm...
my MIL is very me-hostile (and everything about me) but I've learned to just let it go and ignore her... she is very rude to her own son (my DH) so I can't really get very upset about it anymore. We don't see her very often (DH's decision, but I was pleased when he made it!) She does make comments about the things I wear or carry and those comments are an expression of her thinly veiled dissapproval... but it is our money and we work hard for it and don't ask for $ from her, so it is none of her business and I have told her that... which may be one more reason she doesn't care for me.
DH thinks she's just really jealous and resentful, she had a very hard childhood and $$ was very, very tight when he was growing up (4 kids, one income) so she just resents the he** out of anyone who doesn't seem to have "struggled" like she did. I don't alter anything about me when she is around... bags, scarves, shoes, nothing! She doesn't like me anyway, so why bother?
My SIL is PI (purse indifferent). She and I are great friends.