We received a bantam hen and her baby chicks when they were about 3 weeks old. The species is unknown-supposedly somewhat wild hens that come every spring down to a chicken coop to have their babies. Our friend brought us the mommy and 5 chicks and they assimilated well into our already existing coop and run with 10 hens -the mother hen is EXTREMELY protective and runs off any hen even giving a sideways glance in her radius. 4 out of the 5 chicks have grown and matured and are about 10 wks old-very healthy looking. But one is still just a bit bigger than the day we got her. She eats and drinks but is just still so slow and lags behind a bit when all the others move on from where they have been scratching. She peeps ( i am guessing she) when she realizes she has fallen behind and then runs to catch up with the others, and she will peep when we pick her up. She occasionally sits with eyes closed and appears to be a little shaky/ quivering a bit. Each morning we think that it might be the day she just doesn't make it, but then there she is...She is approx. 1/3 the size of the others. Any ideas what to do for her? Any thoughts that she might make it?