If I have 2 kid ages 4 and 6 and am stay at home mom, is there any chance I will get my kids if I committed adultry?

Broadly, the California Family Code allows the court, during the divorce or at anytime thereafter, to make an order for the custody of a child during minority "that seems necessary or proper." [Ca Fam § 3022]. The court uses two basic criterias:

1. Safety & Welfare: The court's main concern is to assure the child's health, safety and welfare. 

2. "Frequent and continuing contact" with both parents and shared parenting.

I don't think adultery by itself would stop you from getting the child custody.