Aspirin for Preventing Stroke

My mom has carotid atherosclerosis, and MRI shows that there are cavities in her brain (doctors suggested cerebral infarction). Furthermore, she has the symptoms of short-term memory loss (she cannot remember what she had for breakfast, she gets lost in the neighborhood), irritability, etc., doctors suspect that she may have vascular dementia or AD.

My mom was taking Aricept (Eisai), Enteric-coated aspirin, a Chinese medicine that contains Statins, and Ginkgo biloba. But she found purple area on her body (probably Purpura), and the now has stopped taking all drugs except Aricept.

She does not have high blood pressure, no heart disease, no high blood lipids. Her blood test shows that CHOL, TG, HDL, LDL are within normal range. R80 whole blood viscosity, ESR (20. 0 MM), and RBC (0. 45 L) are beyond normal range.  

Aspirin is used widely to prevent strokes, and treat vascular dementia as well. However, my mom has purpura after taking the drugs, does it mean that she cannot take any blood thinners, as potentially all of the blood thinners have the risk of causing bleeding. she was taking asprin 100 mg/d, together with statins, Ginkgo biloba (also an anticoagulant). Could she reduce the dose of aspirin, instead of stopping taking it at all? (Or stop taking it together with other blood thinner drugs like Ginkgo biloba).

Thanks! Your help will be greatly appreciated.