Congrats! =) Before she's ready to blow, she should look like she's packing golf balls - personally I think pregger mice get to looking way more pregnant than pregger rats...

Anyway, it's up to you if you wanna try keeping the 1.3 together or putting the mom in her own enclosure before she drops. Personally, I'd put her in her own enclosure as I've not had the best success with multiple mice in an enclosure with a mom who dropped ("ooh! look! *nom*"). I'm thinking 1.3 with a litter of babies is a bit small for 10gallon, but then I always separate out the mom, regardless of what size cage they were in while in a group. =)

Get ready for the cutest, highest pitch squeakies ever!