You always have the word :-)

I always tell my married male friends that they always have the last word -- Yes Dear.

But seriously your position as a parent requires that you are sensitive to your spouse. As the Mother she is under a new stress - Motherhood. So look for ways to reduce that stress. Cleanup after a meal. Do the laundry. Run to the store for those things she needs. Make the bed. Run the vacuum. Remove the protective covering [aka. dust] from the furniture. Let her sleep in when junior decides to arise early. Take that 3am shift feeding [if possible]. And remember those special treats she likes. Surprise her with them OFTEN.

Raising kids can have times of conflict. Work TOGETHER to come up with solutions that you both can support. And this should be done in private, out of the ear shot of the child. Don't allow them to be put in a position of coming between you and Mother over the ISSUE. Once the discussion is concluded, close with "Yes Dear".