Father not giving almost any money to my mum, not caring about her at all?

My answer is going to be very short . Your mother should divorce him ...she will manage on her own ...lots of women even with young children manage on their own . Encourage her to find her self esteem, when she finds her self esteem , she will find her ...Pride / dignity / and her self respect ...then she will walk away from this abusive relationship and never look back .