Kudos to you for stepping up and taking care of this little girl.
And congrats on becoming a grandma!
I have often seen it stated that you shouldn't bathe a female just after whelp. I have always given mine a 'quick bath' afterwards. Once the pups had all fed and eaten. I would rinse and wash just her bottom, using baby wash and make sure she is dry and warm before putting her back with the pups. But that's just me. Never had any issues. In my mind, 1) gals are a mess and it's gross 'back there' when all is said and done and 2) I can't imagine that not cleaning them up is sanitary and bacteria free.