I am wondering what town in Westchester has the most "walkable" town center?

My wife and I are greatly interested in moving from Brooklyn to Westchester. But because my wife had a stroke a year and a half ago, she cannot drive. We need to move to a town that she walk from the house into town and do some shopping, go to the library, etc.

What towns fit these requirements?

Thank you in advance for your assistance.

JonF