I don't know...like with people, it depends on the mice. Just as some women conceive and deliver babies into their 40s or even 50s (such as Dawn Brooke) without problems, some mice do as well. And then again, a pregnancy over age 35 is very risky for other women.
I've heard it said that mice never fully go through "menopause" the same as people, just that their fertility drops (and doesn't end) after nine or ten months. I know a mouse who had a litter after one year of age and all was fine. The breeder did cull the litter pretty heavily (I think down to 3) so as to not make it too stressful on the mom.
I, myself, let my does have 1 litter at about 12-14 weeks. Once they have had there litter and they have been sexed mum goes into recover for 2 weeks and then goes in with the buck again. This will be her final litter, unless her babys are really really good then she may go on to have another litter So we are looking at about 6-7 months i suppose for my girls.
For a first litter, 8 mo. is a fair limit, and I would not breed a doe at all after 1 yr. Earliest for breeding I'd put at about 3 mo., thought some breeds that run to obesity I might start at 10 weeks.