The 0-3 months worked for Sammy and she is 6lbs so you're probably fine! I had to find a skinny one though. Most of them were too wide because they have to fit over big diapers. I found one that was a onesie and pants set and the onesie was much skinnier and that worked better! I got it at Carters.
I would definitely have someone watch her. I had to hold Sammy for like 2 days because she was trying to get at her stitches and I felt bad and didn't want to put a cone on her so I just sat with her. All her grandma needs to do is make sure she doesn't bother her stitches and that she can go potty a couple times. Otherwise she will just sleep. You guys can watch her over the weekend and by Monday she will be feeling a LOT better.
Also when Loki got neutered the Deramaxx gave him VERY bad diarrhea. Sam got Rimadyl and she was fine. Really I think she needed it for about 3-4 days and then she was wrestling with Loki so I think she felt better.
