What is the ruling on a mother helping her son with marriage if she is capable and well-off, and he is incapable and in need?

If a son needs to get married but does not possess the means, the capable father is obligated to marry him off, because marriage is part of the obligatory maintenance, as stated by Al-Mardawi and Ibn Uthaymeen. If the father is in hardship and the mother is capable, she is obligated to marry off the son. As for whether she can seek reimbursement from the father for what she spent, there is a difference of opinion among the jurists.