Mother not happy with the girl one wishes to marry

I am 24 years old and I am Bangladeshi. I want to marry a woman who is 11 years older than me, Pakistani, divorced and has a five year old child. As you can see I face monumental hurdles to convince my mother. I am aware that I don't need anyones permission to get married, however, I want my mother to be happy with this marriage. So far I have mentioned to my mother that the woman is Pakistani and my mother has refused even though I have explained that in Islam this is not an issue. I would like to ask the mufti what I can do to convince my mother? I am making plenty of dua that Allah softens her heart and makes her accept. I am also subtly talking about the issue. Also, what can I do if my mother doesn't agree? Is it a sin for me to marry without my mums consent or would it be a sin on my mother for preventing this marriage?