Uh, no.

This is quite simple.

"Estimate the probability the nun passed some point on the path at the same time on both days."

First off, the graphs presented are bogus and meaningless.

Let's break this down to two lines demarcated 0-12.

Upward Leaves at 7:30 AM (Sunrise is later in a valley)
Arrives at 7:30 PM (Sunset is later on a mountaintop)
Steady climb up:

0 1 2 3 4 5 6 7 8 9 10 11 12
7:30A 8:30A 9:30A 10:30A 11:30A 12:30P 1:30P 2:30P 3:30P 4:30P 5:30P 6:30P 7:30P

Downward Leaves at 7:00 AM (Sunrise is earlier on mountaintop)
Arrives at 7:00 PM (Sunset is earlier in a valley)
Faster downward travel with substantial siestas:

12 11 10 9 8 7 6 5 4 3 2 1 0
7:00P 7:35A 8:15A 9:00A 10:00A 1:30P 3:00P 3:30P 4:00P 6:45P 7:10P 7:30P 7:00P

Note that there is no ‘intercept’ point in combined space and time at any of the points (even if you increased the granularity it would still be so), so there is no “same point on the path at the same time,” provably showing it cannot happen 100% of the time.