Raising a child is both responsibility and happiness of a mother. Because the love she gives for her kids is so big that she could do anything for her kids to have a better life.
That mother does not want her kids to pay her though. What she wants the most is that her kids can have a happy life.
However, the kids sometimes could not take care of their mother. May be the love of the kids for their mother is not big enough, or not as big as the love the mother has given to them.
Or maybe they have not overgone what their mother did, so they could not understand the mother’s need and wish. They think their mother has taken care of 10 kids, then she could manage her life too.
And more seriously, they are afraid of the responsibility to taking care of someone. They want to push that job to the other brothers or sisters. Their mom, instead of being their big love, is now becoming their burden.