Re: Ginny. Might she have been a disappointment for the Weasleys? They might have been expecting a seventh son, and instead they got a girl.

I always interpreted it as Molly and/or Arthur wanting a girl (since there hadn't been a Weasley girl in some godawful long stretch of time) and just continuing to churn out children until they finally got what they wanted. Which doesn't necessarily preclude her being a disappointment to them. If they had some convoluted idea of what a daughter was supposed to be like and Ginny didn't fit the mold, they could be disappointed with her. Molly in particular seems to very fixated on her kids fitting into a mold rather than appreciating them for themselves.