This is official art from Megami's May issue which, correct me if I'm wrong, isn't suppose to be on danbooru.

Official art can be on Danbooru. There's a tag for it.

OK then, I can verify it's a part of a page from the special Madoka booklet in May 2011, issue 132 of Megumi. They're official character drawings, so the artist would be Ume Aoki.

I'd tag it aoki_ume but is this hers or by the animation crew?

Also, really interesting to see these characters drawn anime-style.

@shadowstalker. I'm pretty certain it's Ume-tentei's because she did all the original character design concepts. Plus, the father and younger sister never appear in the anime with these designs. The animation crew went with the SHAFT-approach of cool-looking cardboard cut-outs. Here's the full-scan page where it appears if you are curious: http://i54.tinypic.com/2mnelih.jpg

Original character design was by Ume, though character design in general (ie. what was done to work for animation) was done by Takahiro Kishida.

Hm then I'm not sure since the father and younger sister didn't show in the anime with these designs, since these are concept designs. Young Kyouko did briefly in a couple seconds flashback.

"Promotions!"