weining babies/ biting mama

Question
we got 2 female rattys (snowball %26 shadow) about 4 weeks ago. when we got them (we did not know that snowball was pregnant)they did fine being together. almost 3 weeks ago snowball had 12 babies. (only 9 lived and are doing great) we did separate them as soon as we found she gave birth. we assumed to leave snowball alone with her babies was the best thing to do. Was it? she has been a good mama, but recently has started biting us, hard. we did let her come out last week so she could play with shadow in the other cage and get away from the babies for a bit. she did fine, they played. let them play like that for couple days for an hour at a time, and now when ever i reach in the tank she lunges at me and bites. i read that giving her time is best, but not sure how long it should take? i am scared she will hurt shadow if i put them together again. Really not sure what to do about it. i am even afraid to feed her. (don't worry i still do). i have been giving grapes to help the babies with the weaning, and they are tasting them with little nibbles. Guess my questions. are do you have any advise as to what to do about Snowball(mama)? also can i let the babies in with the other rat or will she get aggressive too? please help! any advise would be great! thank you!

Answer
Mom will chill out once the babies get a bit older. Put on some oven mits and remove mom to another cage so you can handle the pups. They MUST be handled in order for them to be social. She will slowly come back to her old self once hormones level out, too. I  would let her mingle with the other adult rat but dont let the adult around the babies or this may make mom rat go bonkers on her.