Is this normal behavour at 7 days old?

Question
While at the Humane Society the worker picked up an igloo to show us one of the new arrivals and was very distressed to find a brand new litter!  They needed a foster home quick, we volunteered.  Aside from our tired eyes from all the Internet reading things have gone well.  One cage mate and momma, 15 pinkies.  Only now at day 7 they aren't as pink. :)

Here's why I am writing, I just want to know if the following is normal, if our reaction to it was okay, and how to respond from here.

The momma rat just took the babies out of the igloo nest and split the 15 into three groups kicking cagemate out of the kleenex box  we gave her as a hidy-hole and putting 3 babies in there, 3-4 on the bottom level tucked in by the food dish and the rest stayed in the igloo. Then she was rough with the cagemate continually pinning her and nipping her.  I removed cagemate and gave her a makeshift cage (it won't do for more than a day). With cage mate out we gave momma more paper towels and she filled the kleenex box then retreated to the bottom level.  

One baby was crawling out of the box up on the upper ledge, I was worried it would fall so I risked a nip from momma and picked it up.  It was cool to the touch (unlike our once a day "socializing time when they have all been warm) I kept it with me for about an hour cupped in my hand, it was fast a sleep and warm. During that time momma calmed down so I put the baby down on the lower level with the other small group. At the disturbance she gathered those ones (the ones on the lower level by the food dish) up and tucked them away in the igloo but didn't check on the two left on the upper ledge.  I waited, mom and I watching each other out of the corners of our eyes (we are both tired).  While I'm writing this it became feeding time, I brought the two out of the box and set them in front of the igloo.  Momma just took them in.  

The cage isn't great, it's what the humane society put 2 adults in. It's big so when they are 3 weeks they will have room to play I have put a hammock like safety next up to protect the adults from a fall off the upper ledge but the babies with eyes closed could tumble down a ramp or... anything.

Anyway I would love to know you thoughts and even if you think every thing will be fine and need to answer more pressing questions, it was a comfort to write you as a distraction at 3 in the morning. Having you answer so many questions is a real blessing THANK-YOU!! Answers to other people's questions have be so very helpful to us.

Now that they are all in and getting fed, I'm getting some sleep.

Answer
Mom is scared and doesnt like her surroundings.  Usually they dont like other female adult rats around her pups and will attempt to hide them.  Its best you took the other female out.
However, the best thing to do is put mom and babies in a smaller safer cage, single story is best with bars that are close together.  The babies will start roaming when they open their eyes and the cage that they are in is not really suitable for young pups. They could be injured seriously from even a fall from a low shelf.  I would get a single story cage from the pet store that is around 12x24, no shelves etc... just give mome an igloo and she will be happy being able to keep her pups close with her and have no other adults making her feel that her pups are in jeopardy. Momma rat doesnt know you from Adam of course so this makes her feel even more stressed. A stressed mom isnt always a good mom so its good she seems to be worried about her babies enough to try to hide them.

Be sure to feed mom some soy milk and scrambled eggs, and also white chicken breast to get some quality animal protein in her. This will help produce a good healthy milk for her pups.

Hope this helps and please feel free to ask anything anytime, even if it says you have used all of your follow ups you can make a new question again just remind me where we left off. LOL
Thanks also for taking these babies and their mom in. Its not easy to foster these rats and have to get all attached and let them go again.  Your doing a great thing!