7 week old chick

[Bhaake]

I have a 7 week old chick that was hatched and raised by my hen in with the other two hens that we have. It looks as though momma has started to distance herself from the chick but today I noticed momma pecking at the chick’s breast making her cry. When I took a closer look at the chick it looks like it’s been happening for a bit because there’s obvious feathers missing. I don’t think it’s a constant thing but I also don’t want her to get hurt. Why is she pecking at her baby and what should I do? It doesn’t seem to be getting picked on by the other 2 hens.

 

[ChickenCanoe]

Their eyes are much better than ours. Perhaps she sees lice, mites, ticks or other parasites on it.
This time of year, it isn't unusual for a hen to wean the chicks at this age. At 7 weeks and they are no longer babies. Actually a hatchling can survive on its own if it can find water, the temperature is warm enough and a predator can't find it.