In the example you give, your mother was compelled to choose between her adult child and her husband. How do you think *she * felt? And for either of you to try to make her feel bad doesn’t sound right at all. If she had helped her husband instead of you, would you be telling her she had done the wrong thing?
I think parents owe their offspring pretty much everything they can give, *while they are children. * But when they become adults, they need to be treated like other adults and judged by the standards that would apply to other adults. In the extreme, that might mean that you don’t give money to someone who squanders it, or even that you press charges against an adult child who commits crimes. In the example you give, I think your mother was entitled to decide which of two adults in her life needed her help the most, and she could rightfully have decided either way. Is there something else going on here, like maybe some friction between the son and stepfather?