Housing Females together?

SO I have started a colony of rats 1 male 2 females :) Both the girls are pregnant about a week or so appart I think. My question is this can I leave both females together to nurse and wean the babies. The are both sisters from the same litter and have been housed together the entire life. I plan on taking dad out in the next few days so I do not get another litter back to back but just wanted to know if it was ok to leave the moms toghther. I have heard from not so reliable sources that sisters would be fine as long as they both had babies to take care of but if there was only 1-2 babies they might fight over them. I plan on growing these guys to 40-60g and have grow out tanks to put them in. Please let me know what you think
Thanks in advance
Erik

They will be fine together regardless if their sisters or not. My breeding groups are 1.2 or 1.4 depending on the rack and I have never had a problem keeping them all together I don't even take the male out and I have never had any issues I just pull the babies once their wened I've been breeding rats for almost 10 years now

^^nearly identical to what I was going to post....

I leave mine together providing they give birth around the same time. Rat pups grow really fast and even a few days apart make the first litter bigger and stronger and they can steal ALL all the milk! Yes even with 2 moms worth! So I would change females around till I figure out which 2 were close and then keep them together, wearn their pups at the same time and introduce the male at the same time as well!