Deductions on final return of a person who died this year.

Yes ... you will prorate the annual expenses between her final return and either the estate's return or the beneficiary's return. 

I highly recommend you seek local professional guidance to get the final/estate returns filed correctly. 

Thank you. That will be a lot easier than figuring out every deduction amount month by month. Since the income on a vacation rental varies widely month to month should I prorate the total for the year or report the actual amount for the three months she was alive? 

For income and expenses that differ monthly you must add up each month separately.   Only with annual expenses like insurance or RE taxes can you prorate the costs.