Could I get some advice for a friend?

I have a friend, she lives in New Zealand and has a couple of pet rats, they were pregnant when she bought them. She sent me this message.

'I have 2 very friendly litter mates ( sisters ). They never fight and get along really well.
Is it ok to have a heavily pregnant rat.. with my other female that just had babies today??
They both have their own separate box's to crawl into and nest / nurse. And my pregnant rat just seems to stay out of the way of the one with babies.
I have read online that its ok, but some people say its not. Arghh i dont wanna risk them eating each others babies, id be devastated'

With no experience of breeding rats myself, I don't know the answer. I was wondering if anyone could help me answer her question, particularly Laura. :-)

Thanks.

As far as I know the mothers will usually not eat the other's rats. On the contrary, sometimes they will even nurse each other's babies. If one of them gave birth before the other one, the pregnant rat's mother instinct might kick in and she could steal the other one's babies for herself , so keep an eye on that. Otherwise it shouldn't be a problem provided they both have their own shelter.

She may end up not knowing which babies belong to which mother, but if that doesn't matter there probably won't be a problem. Having said that, I'd not be comfortable with it, a doe may kill strange babies, or the two does may fight badly if they are trying to protect their young. Chances are it'd be perfectly fine (I know some breeders do creche their litters sometimes), but it would make me feel uneasy.

xx

Thank you both for your answers. I've forward your responses on to her. x