<p>The mortgage + taxes + insurance + condo fees will probably run you $800-900/month (maybe more), plus whatever the opportunity cost is of the $45,000 you are putting down. This doesn’t factor in repairs and renovations that you will have to pay for as the owner. When you buy it you will have to pay several % in closing costs, and when you finally sell the place, you will pay another 5%+ in commissions and other costs.</p>
<p>You will have to weigh the risks of the value going down vs. making a profit if the price goes up.</p>
<p>Furthermore, getting financing for condos is extremely hard these days, especially if it is not going to be owner-occupied. Many lenders won’t touch a condo unless the development is more than 50% owner-occupied.</p>
<p>What can you rent a comparable apartment for? If it is anywhere close to what your monthly carrying costs are going to be, I would rent. Fewer headaches, you can more easily move her if you need to without having to sell something, if she has any income at all you might be able to get away with the lease having her name on it rather than yours (even though you are going to help with the rent), which lowers your liability.</p>
<p>Unless you are sure she is going to be there for years, I think renting is the better option.</p>