We've got a potential camper around the house, about 2-1/2 years old. I've been looking at bags for her to try out in our back yard and maybe someday summer nights in the Sierra. We're in the SF Bay area, so I'm less concerned with temperature than I am the basic shape. I started out with ye olde Coleman rectangular.

You figure just get her a rectangle at this point? Maybe the mummy style bags they have out there will be a little restrictive (she is far on the active side, even when trying to fall asleep).

Thoughts from those who have had kids grow through bags? How about mattresses? For now, she can use her Mom's thermarest, backed up with our Z-rests.

I got my daughter a north face blue ridge 20 bag a when she was about that age and I wanted her to stay warm in a sled I was pulling on skis. She has used it more lately camping. Before that I just let her use one of my older bags and tied of the foot end to limit her travel. I would still wake up and make sure she was covered as she would sometimes kick it off. A thermarest should work fine.

Tying off the bottom . . . hadn't thought of that. Brilliant!