There is no age limit to breeding in VV1. In VV2, once they reach age 50, the females can no longer bear children.
As for the cauldron, it depends upon how you want to play. I often get the cauldron before Farming L3, and rely on stew to keep my villagers healthy if food supplies get low for some reason, even though they have the farm. Picking a few mushies lets me make a stew that will really help the peeps. Of course, you have to be keeping an eye on things to prevent disaster.
