FWIW, I ended up getting my daughter a Winchester SXP Compact 12g gun; a buddy of mine had just gotten it, and decided he wanted to get a Mossy instead, so I scored a pretty good deal on it... It's small & light-weight enough for her to grow into, and I've outfitted it with a Tru-Glo front sight, strap, and a Primos Tight Wad choke tube.
Took her hunting yesterday morning, and she ran out of gas by 9am; went back out with the gun @ 9:30am & took a bird with it. Pretty sweet gun, imo, and came with several different choke tubes, so it should be the one & only gun she'll ever need (while hunting w/me).