Make sure sister gets tons of food and kitten formula to drink. She’ll need it to care for 8 kittens. Weigh mama’s 3 daily to make sure they are getting enough milk. Mama will want her babies back soon! Glad she’ll be okay.
Poor Mama! She's really been through it. Thank you for being so attentive to her needs. And to those of Big Sister, taking on all of the kittens till Mama is feeling better!
Probably too late now, but it might be a good idea to rub mom cat down with a blanket she's been using before putting her back with her kittens. They may be put off by the unfamiliar vet-scent on her.