The mom's still with them. I gave them some water and some cat food, but I think they've been up there for a little while because the cat's eyes are open, if just barely.
Discussion
Then continue observation at a distance.
Mallory is correct. Patience is critical here
(I foster abandoned kittens)
If you’re willing, keep feeding the mom. It will allow her to stay close. You could even see if she’s willing to move inside with them. She might move them to a warm spot with food and water readily available.