The question was "Estimate the probability the nun passed some point on the path at the same time on both days."
1. "some point on the path" - a fixed point in space
2. "at the same time" - an exact time
3. "on both days" - happening exactly 24 hours apart, down to the millisecond
That the paths intersect is a given. That they intersect at exactly the same point on the path at the same exact time down to the millisecond exactly 24 hours apart makes it all but impossible.