Thank you all for responding. I will post pictures. A little background: she (Bonsai) had a small opening on her umbilical, but it closed with no sign of infection. Her air cell was very small at hatching and she did not grow (at least noticeably) for a week. She has been eating, drinking, pooping. She moved less than her siblings and her legs were weaker/slightly bowed. I have been giving her electrolyte/vitamin water daily (as well as plain fresh water). When the next round of eggs began hatching, I moved her largest siblings to a bigger brooder (out with the adults), and put the new hatchling in with Bonsai. She has begun growing more now and moving faster. The new hatchling is 8 days younger than Bonsai and they pretty much identical in size (Bonsai's feet are still quite smaller). Bonsai is 12 days now.