We sacrificed 92 months of our lives to take care of our beloved mother , but we think that we should be compensated for the the hard work that she required.
clavecin, the vast majority of grown children who were caregivers for their parents are not paid, unless the parent(s) paid them from their own retirement fund while said parent was alive.
I agree with AlvaDeer's posting. Your brother and you should have had an written employment contract stating your duties, the number of hours each day, the hourly rate, etc. Doing this after the fact usually isn't successful. Sorry.
You cannot get monetary recompense for past care given unless that remuneration is agreed to by heirs of the deceased's estate. You can agree to payment, get a care contract drawn, and etc while you are giving care, or before you begin to get care. This payment is them kept by record, and becomes part of your yearly IRS statements. Should the person you gave care to without any payment die, and should the heirs of the estate decide, out the goodness of their hearts, to give you money, that is up to them; they will however have gift tax concerns if this is done, because it cannot be claimed as "payment".
I agree with AlvaDeer's posting. Your brother and you should have had an written employment contract stating your duties, the number of hours each day, the hourly rate, etc. Doing this after the fact usually isn't successful. Sorry.