I had a workaholic who became master at the age of 31 and I only had the first upgrade then. His wife had 6 kids and mastered at 42 (also with level 1 upgrade). And I didn't do anything special for them, just praised while they are working at the beginning. All my families had 6 kids so far, except for the new gens which are still young (though some of the kids were adopted) and all mothers except one (job infiringments) became masters but much later then their hubbies.