Property right of minor son if father expires

If her old husband had left any property (without making any WILL or without gifting it to anybody during his life time), then both your friend and her child will get the property.  If her first husbands mother is also alive then she will also get a share in the property.  If the mother of her earlier husband is alive, then the property will be shared at the rate of 1/3rd each.

Therefore, what is to be first ascertained with certainty is whether her past husband had left any property.  If so, then she has to ask for her and her son's share.  If they are not giving, then she has to file a civil suit for the same.

Her son from earlier marriage will not be eligible for any share from the property of her new husband, unless the said son had been adopted by the new husband.