I am not certain why you titled this as your marriage falling apart... your wife was able to stop the medication to have a child with you. You say nothing about how she feels off the medication, is she aware that you have such a strong opinion of her in regards to her being off Effexor ? According to you she probably has some issues due to her childhood, Maybe she would look into Therapy.

Enjoy your beautiful baby girl and be supportive of your wife.