Help!!

Hi everyone! I'm new to everything chickens. I just got a 1 day old baby chick and I'm very concerned about her. She has what looks like a boil on her lower tummy. It's inflamed, hard to touch, and has pusculions coming out. I have put a very small amount of peroxide on it, and am worried that it will harm her. I've also put a homemade sav on her that contains iodine, and campher in it. She is much smaller than the other chicks. We just received them today.. so I'm not sure how long this has been going on.. but a couple of the other chicks had her laying on her back pecking at her. I have her alone with a heating lamp and I am checking on her frequently. She is chirping A LOT. Any advice or suggestions would be greatly appreciated!