what does queda mean?
Example: La ropa de mi hermana mayor me queda...
The clothes of my older sister ( me queda)...
In this case, to fit.
La ropa de mi hermana mayor me queda=My older sister's clothes fit me.
I think in this sentence it means to fit
I think it would translate to ....
My sister's clothes fit me best
Sometime "queda" is used instead of "está".
In your sentence you have "My older sister's clothes look _____ on me"
Is this a homework assignment? If so, there must be a section somewhere in the chapter that deals with "quedar" and its uses.