Bad Mommy Rat

I just started breeding rats not to long ago. I put two pregos together in a tub and they both gave birth to 11 pups each, one day apart from each other. The rat who had here litter first is nursing all 22 babies. The other rat just sits in the corner opposite of the babies and is not nursing any of her own. Should I just leave her where she is, or should I put her back into a breeding tub to make more babies, or should I feed her to one of my snakes and get rid of her?

Leave her there until the babies are weaned, usually females take turns, she is probably nursing when you are not looking.

To really figure out if a mom is a good mom and is nursing or not you need to set her up individually than you'll know for sure.

It might not be her not wanting to nurse it might be the other female stealing all the babies for herself.

Let the be they will figure it out.

This happens more when you place them together just before they drop babies.
When raised in a group I've not had that issue but agree with Deb, leave her be so she at least sees what it takes to be the mom :)
I bet you find them both nursing in no time at all.