Because of the stroke, which I am assuming was caused by a clot in the brain since they are treating her with blood thinners, she needs to be on a thinner indefinitely. If she takes nothing, the chances of her having another stroke related to a clot is high.
I am not sure if her physician would be agreeable to try a simple 81 mg baby aspirin with her. Plavix is another blood thinner that is prescribed also.
I've found that Aggrenox seems to work without side effects. It's primarily baby aspirin, but also contains a drug that prevents platelets from sticking together. I've taken it twice a day since my stroke, and it appears to work, but who ever knows?