Woofgang is a retired Occupational Therapist :) I do keep up a bit with latest research. Sorry but i don't have much to say that is encouraging.
The problem with stroke is it doesn't just affect the nerves which control the muscles but also balance, the body's knowledge if where it is in space, concentration, and so on.
Its absolutely correct that damage to the brain can be minimised by fast treatment but once that acute stage is over and the damage that is done is done; then its impossible to predict what or how much recovery there will be. To further complicate matters, as Sqad says it depends a great deal on what your Aunt was like before her stroke....additionally there may be previous damage from small unnoticed strokes which is now causing problems for the first time.
Actual neurological recovery happens first of all by the restoration of blood flow/nerve function to the affected areas of the brain. Inflammation and swelling goes down relieving pressure and temporary impedances to function resolve. This is where we see early "miraculous" recovery. After this sometimes other areas of the brain take over functions from the damaged parts This is where rehab of all kinds is important, practicing simple, and then increasingly complex body movements over and over again to encourage the brain to retrain. Thirdly there is what I would call "functional" recovery where the person learns to make the best of what they have left, learning new ways to do things with the remaining function that they have.
When I was a part of setting up stroke care protocols many years ago, it was, as Sqad says, believed that 12 months was the most likely cut off point for seeing neurological improvement....personally (and we did our research) I think that six months is more likely, especially for older people. In case anyone thinks we scrapheaped people, there was a clear path to get back to re assessment and active rehab if either neurological or brain retraining improvement seen after 12 months. We didn't see many takers :( Brain retraining improvement probably will also have occurred if it is going to, during that first year. Sadly depression is often a post stroke problem. It is usually a mixture of the bereavement following any seriously disabling event but it is thought that there is also a neurological element caused by the stroke damage.