Lav Orpington help

We got 5 chicks, all hatched around the same time. Our Lavender orpington is very tiny.

We have a Copper Maran (Edna-she is huge), 2 easter eggers, a sapphire gem who is a bit tinier than easter eggers and daisy who is like...half the size of the sapphire gem.

She is eating and drinking. Today though, I noticed she sits a lot. Like A LOT.
She is so sweet, just so tiny.
Should I be worried?