"Rent to own" homes are reserved to typically only a very small portion of the properties available. This may vary in your market of course, as I can only speak for the Chicago area. These homes are typically geared towards people without sufficient income, or credit, to qualify for a mortgage - but "plan" on being able to qualify "down the road" at some point. While they are advertised as "rent to own" they should really be called "rent to save up a down payment" because in essence that's what they are. In return for the owner essentially "holding" the property for you, while you rent it and improve your finances - you get to assume a lot more risk than the average tenant would. Personally, I would not recommend your mother get involved with one of these, however if you do - I've laid out some of the general details below.
Lease to own homes are laden with pitfalls for the buyer and an exceptionally bad idea in my opinion. They are not an easy way to buy a home without having the sufficient credit, income, and down payment to do so, as most people seem to believe. Here are some reasons why they are a monumentally bad idea:
1. You'll still have to typically come up with a lump sum (essentially a down payment) or "option" to enter into the agreement. This is due upfront and is usually a percentage of the purchase price. Plan on a certain percentage of the purchase price (1-2%), which can amount to thousands depending on the price of the home.
2. You'll agree on a date when you'll have to exercise the option to buy. Let's say 2 years from now. At that time, you'll still have to qualify for a loan, and have sufficient down payment.
3. If you pay the rent late even once, the seller typically reserves the right to keep everything and void the deal.
4. How do you know the price you negotiate down the road will still be a good deal when it comes time to actually purchase the property? Will you qualify for the financing then? Will it appraise out?
5. You'll be responsible for the upkeep of the property throughout the life of the lease. If the furnace goes out, you'll have to fix it. Same for the roof, plumbing, and everything else. Remember, this is for all intents and purposes now "your" house.
Violate any of the above terms and the seller keeps everything you gave them upfront, and also all of the money credited towards your down payment from each month.
Too much risk, too much money, and too much uncertainty about what your situation or finances will be too far down the road in the future, in my humble opinion.
My advice would be for your mother to simply do a traditional 12-24 month lease, until she is confident that the area is where she wants to settle down & stay for the long term, then purchase using traditional means after that if still interested. You could always ask the owner if they would be interested in possibly selling at the end of the lease, without having to enter into an option agreement that is going to saddle her with extra risk.
Hope this helps!