Mom huddles in corner of cage

My chin recently gave birth to two kits. She seems very loving to both of them. I've found her to sometimes huddle herself in the corner of the cage as if she's denying them milk for a bit to let her sleep.

I've been thinking of hand feeding them with goats milk or separating them from the mom for a bit to all her to sleep.

But I just wanted a little advice before I take action.