I recently came online and see that your question about hasn't been answered. I'm so sorry that you've had to wait for a response, but if you still need assistance, I'd like to help if I can.
As long as you aren't giving Kizzie drugs which would be then transmitted in her milk to the nursing pups, it should be fine to put her back with them in a few hours.
In addition to the bland diet you mentioned (I suggest 1 part boiled, skinless, boneless chicken breast to 4 parts 20-minute boiled white rice, multiple times through the day), I might also start her on a probiotic such as Forti Flora.
I wouldn't feel comfortable suggesting any otc medication for her while she's still nursing; in fact, we have to be careful about drugs dispensed by a vet for nursing moms. But, if the puppies are pretty close to be completely weaned (which they should be), then she can be treated appropriately if the diarrhea persists as long as they don't nurse.
I hope this helps although, again, my profuse apologies for the delayed reply. Deb