The phrase "to become a stay at home mom" means to choose or decide to be a full-time caregiver for one's children at home, rather than working outside the house. Full definition
Do they see themselves working throughout your marriage or are they thinking of becoming a stay at home mom or dad? (protective.com)
After working in the fast - paced corporate world, I made the decision to become a stay at home mom once my eldest daughter was born. (elizabeth-finch.com)
When I unexpectedly became a stay at home mom, we switched over to cloth only. (theclothdiaperwhisperer.com)