Oh goodness I can relate to your feelings. I have 2 older sisters and the 3 of us are very different in a lot of ways. I am closest to my middle sister though I don't get to see her often.
I remember clothes and style being important from the time we were very young. Going shopping downtown was an event. We didn't have a lot of money but we always had good shoes and appropriate clothing for school and for church. At Easter, we would all have lovely dresses (often matching) complete with patent leather shoes, spring coats, gloves and hats. When I was 5 or 6 I modeled for a nice children's store, though we probably couldn't afford to buy much there.
As a young teen, my mom managed a very fashion forward clothing store. I recall accompanying her to New York on buying trips. Later she wholesaled women's clothes. When she was 18, my sister moved to NY to work in the fashion industry.
A lot of background just to say that clothes have always been a thing in my family!
Anyway....my sister went through an awkward stage in childhood when she was very thin and had short hair and was often mistaken for a boy. But boy did she blossom! She became a gorgeous woman as an adult and she has a knack for looking sylish. I remember plenty of times when she would borrow clothes from me and always managed to look better in them. But her beauty is not just skin deep. She has a bubbly personality and an extremely kind and caring heart.
Today, I am able to shop more and buy more than my sister can. Yet with a much more limited wardrobe she still manages to look way more stylish than I ever will. Part of that is that she has a much nicer figure than I do and styles are more flattering to her. So it is easy to feel frumpy next to her.
I hope I don't sound jealous because I truly am not. I adore my sister and am happy to share my closet with her. Numerous times I have sent her dressy shoes, a bag or jewelry to wear for a special occasion. We no longer share clothes because I am quite a few sizes bigger than she is. But accessories fit!