Ever since their father died about 10 yrs back, their mother is shuttling between India and Dubai. US authorities rejected her visa and hence my friend used to come down to India and spend time with her whenever she could. But since she landed up a job, those visits became rare as you don't get much paid leave in the US.
Aunty once told me she misses not having a son. Her reasoning was that she could have stayed at one place and the daughters would not have been troubled with all the running around. I always felt she is lucky the way she is having blessed with two daughters who have put practicality aside and has been with her throughout.
From an outsider point of view I think the daughters never ever felt the burden. Even now my friend has financial liabilities, but yet she is taking a break and coming to India for her mothers treatment. I am not saying that she is doing it because she is a daughter and that a son would not have done it. But I think daughters are more attached emotionally, whereas Sons are more practical. When a decision has to be made they tend to think over it practically than emotionally.
I have found women who stands by their family whether right or wrong, they say right or wrong is secondary , its family that takes priority. Most of such woman feel let down later on by the same people whom they once called family. Family is a changing concept, for a woman until marriage it is her father , mother , brother /sister, which makes her family. Once married, the definition of "family " shifts to husband, children etc. But the shift in the definition happens for everyone irrespective of gender. However the shift is more evident in males. Guys are practical, once married they know its their wife and kids who needs to be moved up the priority ladder. So mothers feels let down when they see the shift in their sons. Most of my aunts are only blessed with sons, and all of them are married, suddenly I see them longing for a daughter in their twilight of their lives. Not that they do not take care, not that they do not provide them with the comforts, its is the shift that irks them. Shift of loyalties/affection etc.
Relationships constantly evolve, they keep reinventing themselves, it follows the universal rule of change. People who understand this are wise ones. As long as one does not lose sense of humanity, it should not matter to us with any one moving on or shifting gears of life in terms of attachment. The lecture that Lord Krishna gave Arjun when he refused to fight his own kin is very relevant. May be thats why men are more practical in life . Wish I could get him address woman too :-).