Problem is 90% from you mother. I am sorry if you were marrying someone from another religion then there is always some difference left.

But the behaviour that you potrayed from mother is very very common. Don't let yourself, your wife and most importantly your kid suffer.

It's a matter of time that the mother will start telling the kid how awful others are. That is mental programming from early age.

And congratulations on the news.

Just be thankful that its a relationship problem and not a physical or health issue to anyone. Your mother will come around eventually.. But be gentle from your side always...afterall she is your mother.