You could certainly try to request a change in the custodial situation. However, based on the facts as you have provided them thus far, my speculation is that you do not have enough here to prevail.
As a general rule, to change a custodial arrangement, the moving party needs to demonstrate some substantial change in the situation. A substantial change could be that one party has been convicted of child abuse or been sent to prison for a long period of time, for example.
The change you have mentioned, becoming a stay at home mother, is not terribly significant. As such, my opinion is that, in and of itself, this is not a significant enough change to request a modification of the custodial arrangement.
Please let me know if anything requires clarification.
Also, several customers have asked how they may direct a question to me in particular. If you specifically want me to assist you in your legal matter, just put "FOR JOSEPH" in the subject line and I will gladly pick up the question as soon as I am on-line.