No no no!
That's not it, giving out your clothes to her friends was extreme, I for don explode since.
You really were patient enough to condone all her excesses.
I know I used to convert my elder siblings belongings too and just like your younger sister, I tend to wear my sister's clothes and before you know it, it became mine🤣💔😭
My wardrobe was filled with more of my sister's dress than it was of me especially when we were much younger.
But as I grew older and we became distanced, I learned to let go of that habit

I was just laughing and smiling when I read this knowing I've been in this space before but I wouldn't have given out my sister's belongings to my friends, that alone is what I wouldn't have done.