I am a bit late to this. But I feel there is an important point , maybe boundary, to point out.
Respectfully , the history of someone's puberty and weight is irrelevant in asking for feedback on clothes and fitting. I am sure that this young woman is keenly aware of the history of her body. What matters is how to dress it now. Today. And her size yesterday or when she was pre-pubescent has no bearing on that now. ( my daughter and her friends would be humiliated at a public post like this about them. I think that's important. )
Example of what doesn't happen:
Sales woman : I recommend Land's End for you.
Customer : I weighed 10 lbs less pre Covid and was really skinny before I "blossomed" as a teenager.
Sales woman : Oh, then I recommend LL Bean.
I think it's just a matter of being cognizant of doing something that may be humiliating to other women, even if we ourselves donºt find it humiliating... Peace.
And I recommend Landºs end. I dress my intellectually disabled sister who is also very large busted. And their bathing suits are AWESOME.