whats up with my babies

[whorulesdaroost]

hi I got these two 8 week old silkie chicks last week from a private keeper. they've been ok but I have noticed one is defo much more of a baby it issmaller and more fluffy and seems to be needing to be mothered by the bigger one I have. my ex batt hens are not interested if even a little jealous of me holding the babies. but the little one it is really mucky it doesn't seem to do a lot apart from squeak and try to sit under the other chick. I held it today ( don't laugh I put it in my top and it snuggled in my top on my breasts and went to sleep.
im worried this baby may need more than jus to be outside with the others in the house
please any ideas... im desperate shes a lovely girl with a great temperament I don't want to lose her my kids adore her.

thanks xxxx