My daughter turned 18 in January 2011. She is still in school and still living at home. I am a single parent. Is she considered a dependent for the family rebate or would we each be classified for the single rebate?
Your daughter will qualify separately for her own rebate, as an individual, as she will be 18 or older on May 31, 2011, the qualification date for the final OSTTB payment. Note that in order to actually receive the payment, your daughter should file a 2010 income tax return. It isn't too late to do so, if she hasn't already.
Refer to Ontario Ministry of Revenue - Ontario Sales Tax Transition Benefit. Quote:
This also means that you yourself will cease to qualify for the family benefit. You will receive the individual benefit instead, assuming you have no other dependent children under the age of 18. See also Ontario Sales Tax Transition Benefit - Who is considered to be a single individual?