well this is my personal opinion so here is what I believe
First of all, I don't believe that daughters should not help their family co'z they don;t get property from their parents...well I will always help my parents financially or in whatever ways co;z I love them, I care for them and whatever I am today it is because of my parents. I do not expect any financial help in return be it a property or whatever....
Just think about it..this is if you are a girl or (if you have a sister)..what if your parents had not invested in you/(or your sister) ..thinking that one day u (or your sister)will get married and u (sister)will get support from your(her) husband and u (sister)will not give any financial support to your parents in their old days ...so why waste time and money on you and rather they invested in your brother...I know this is still true in most villages in Nepal..and I am completely against this kind of thought or belief...anyways if this was the case then most probably you will still be uneducated ...so arent; you glad that your parents did not discriminate between you(your sister) and your brother (you) and still invested almost equally on both without expecting anything in return..that is called unconditional love that they have for their children....
so now it is your turn to payback what they have done for you ...so I don;t understand why would u even think twice before helping your parents in their old days? Will you only help if you get a property in return?