No, she just mimicked our appearance.
Do you know monster mimic from pathfinder or D&D ?
It can mimic the appearance of a chest, but it is not a chest.
So by comparison, Ella can do the same thing like mimic, but MC can really become a chest.
I think maybe even more accurate would be to say that Ella is Shapechanger. So she can change the size, length shape and some properties of her body. She is literally limited only by her own imagination and that is why her abilities were much better than MC's abilities at the beginning. But MC can touch an electric eel, immediately understand how it generates electricity, and imitate it to a much greater extent. Ella can't do that because her abilities aren't that good. Although in theory, she might be able to do so if she spent several weeks studying this animal, had one of them, could dissect it, absorb it, and then spend quite a long time testing and adapting her own body. As I said, her abilities seem much more limited.