General Terms:
* Крестьянка (krest'yanka): This literally means "peasant woman" and can be used as a general term.
* Мать-крестьянка (mat'-krest'yanka): This literally means "peasant mother" and is more specific.
* Мать (mat'): Simply "mother" works well, but it doesn't specify a peasant background.
More Specific Options:
* Мать-земледельца (mat'-zemledel'tsa): This translates to "mother of a farmer" and implies a specific occupation.
* Селянка (sel'yanka): This means "villager woman" and implies a rural setting.
* Мать-крестьянка из деревни (mat'-krest'yanka iz derevni): This translates to "peasant mother from the village" and is very specific.
Poetic Options:
* Мать-кормилица (mat'-kormilitsa): This means "mother-nurse" and implies a nurturing and caring role.
* Мать-труженица (mat'-truzhenitsa): This means "working mother" and implies a hard-working and dedicated woman.
Ultimately, the best word to use will depend on the specific context and the feeling you want to evoke.