I see nothing wrong with designer-inspired bags like the ones that you're describing (similar designs but not copying labels, logos, etc.). I also see nothing wrong with a young girl carrying a designer inspired bag. It's not like she would be carrying an obvious fake. I don't really believe that young girls should be carrying expensive, designer bags anyways, so her buying a designer inspired bag wouldn't bother me in the least.
ditto.. inspired is not the same as counterfeit.. EVERYTHING is inspired by something. Almost everything you see in the malls is inspired by a runway item. Nothing is that original