I thought of Sylvia because there aren't that many giantesses exactly like her... someone who's bossy, but extremely gentle and caring. There's the weeb aspect too, of course--which is rather unique. You don't think of giantesses as being indoors people, but Sylvia is one. And she's going to do what she can to make sure that she has her comforts in a smaller world.

Diana can come across as rather strong, but she has a caring side too, which I hope to show more of in later chapters.

As for Vicki, she can come across as rather forceful. Let's just say that growing is providing her with something that she's desired dearly, and she's hungry for every last inch.