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?
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.