No. She is liable to send in a form 12 every year to revenue. A quick rough sample would be
Rental income………….€10,800 (12 x 900)
Expenses
Mortgage interest………€ 5,000 (75% of the interest paid that year)
Decorating & repairs….€ 200 (plumbing, electric carried out for the year)
Management fee……….€ 900 (whatever she pays pa)
Taxable profit…………..€ 4,700
Tax at 41%……………..€ 1,927
PRSI at 4%……………..€ 188
USC at 7%..............€ 329
This is not exact but you get the gist. She may be only earning under the 41% threshold, she may have more expenses. She CAN'T claim original expenses prior to letting but she can claim a small percentage of wear and tear once its let out.