B,

Women do not walk away from marriages with infants unless they are abused or there is another man involved. Especially at the age of 30 and only being married for 7 years.

If there is not an OM then she really despises you because women don't typically give up on their marriage this early.

Typically WAWs are in their mid to late 40s and BELIEVE that this is their last chance at happiness. Even then there is usually an OM they have their eye on.