<p>However, IF she is going to pay rent for the condo that you own, and IF this covers the monthly mortgage, fees, repairs, etc., all that you have laid out is your down payment. When you sell it, you essentially get this back plus whatever extra equity you have in it, which she has essentially paid, plus appreciation -though of course you have to pay income tax on the rent and capital gains tax on appreciation - but it may still work out in your favor.
Warning, though - even though she is your mother, she may not pay rent the rent to you if she is having financial difficulties, or she may be late with rent and you will still have to make the payments.</p>