I would sit down and calculate out what you pay for and then subtract the money she provides. You have to think of every little thing (home improvements, transportation, health care assistance, food, etc.) and you may be surprised how much you are paying. Also take into consideration how much she would be paying if she lived on her own. With this information, you would be able to make a better educated decision of how to complete the form. At least if you ever had to defend it, you could.
[This message has been edited by jaskispyder (edited 04-28-2014).]