It should be that all married women are praying for children !
You didn’t say your ages. I don’t know for sure, but I highly doubt my mother prayed for children after a certain age! She prayed for grandchildren.
You cannot convert your wife. That’s the job of the Holy Ghost. Your job is to cooperate with God by persevering in prayer for her. Maybe if you just quit urging her to pray, pleading with her, giving her religious items, purposely praying so she can hear and see you, she’ll think you’ve given up. That could lead her to wonder if she’s really a hopeless case and go to God for herself. If you try this, pray about it first and make no change until you get permission. I don’t know you or your wife, but I know of a woman who converted when her boyfriend seemingly gave up on proselytizing her.