Beth,
My mother sewed alot of my clothes, too, because of the strict length requirement of my parochial school, where only dresses/skirts were allowed. I guess the difference for me was that everyone there was under the same restrictions, so I never felt bad about it. I'm sorry her dreamy-eyed memories don't match up with your own reality. Some of this sort of discrepancy is bound to occur in any mother/child relationship though, I think. I know that my own kids have told me later about something they thought was really goofy and here I'd been thinking I'd really done something wonderful. The key is... I listen and don't feel personally invalidated when their preferences differ from mine. If we were out clothes shopping or something and my mother tried to get me to choose something I really disliked and I said so... she'd get offended and stalk away in a huff.
That sort of preferential treatment she showed between you and your sister is really inexcuseable, I think. (((((Beth)))))
I'm guessing your sister more accurately reflected your mom's vision of herself? In many ways, my brother does that for my mom, in that he's materialistic, money-focused, and his life is one big show.
Leaving all that in the past,
Hope