The Kanji implied that Marisa is her parent, so they are indeed family though.
Doesnt need to be an anko related parent ;--) Or it could be just a (rather strange) stylish decision by the artist. I wouldnt read to much in it. Its a short yukkuri story.
Well, are they smart? Yes. Are they kind? Absolutely. Are they tolerant? Sure.
But if you ask me if they are good at parenting, then unfortunately, no, given the fact that all of their children are either bald and/or have lost accessories.
Probably arent able to conceive their own little ones and adopting whats just around.