Ketubot 53: Details of Post-Ketubah Sustenance

We learn that inheritance goes to the first son.  It should not be given to another son, even if that other son is far more deserving. As well, it should not be taken from a son and given to a daughter.

Women might sell the rights to their ketubot.  This would mean that in the case that the woman divorces, her ketubah money is paid directly to that third party.  The rabbis wonder whether selling the ketubah would affect her sons' inheritance.  What if the third party is her husband?  If a woman sells her ketubah to her husband, this may affect the sons as well.  I cannot find reference (yet) to the ketubah's writings about her sons.  

The rabbis walk through what a woman might be entitled to after she has relinquished her ketubah.  For example, she may lose the right to sustenance after her husband has died; she may lose the right to sustenance during his lifetime, as well.  Another case involves a woman who marries a second time, believing that her husband has died hail while abroad.  She must divorce both husbands, and she and her sons both lose whatever has been promised to them in the ketubah.

The rabbis make a point of noting that a woman who sells her ketubah, whether to her son or to someone else in the community, she must be desperate for money.  

The rabbis move on to discuss how long a father should sustain his daughters.  Until she is married off?  Until she is a grown women? Clearly a man must be sustaining a woman at all times.  Can she support herself once she is a grown woman, regardless of whether or not she is able to sustain herself through employment?

The rabbis then discuss a number of rulings that require debate regarding sustenance.  Theres are cases of:
refusal
yevamot
secondary forbidden relationships,
one who is already betrothed, and
one who has been raped

The rabbis begin to look at these cases one by one, wondering if she will be sustained in her father's help.  Reading their words, if feels clear that the rabbis are working toward protecting women in their structure.  I suppose that this is second best to creating a new system altogether that addresses women's needless vulnerability.