My RIR chicks are 3 weeks old. One chick is barely growing. She is so much smaller she can stand under the others. Also, one talon is turned inward, so she hops to food & water. She is usually under the heat lamp, but does roam occasionally in the tank. What's wrong with her? I don't want to get rid of her if she's just a slow grower & her handicap. Thank you!