Vent Latch 20-013 on a Pella wood sash

I've never tried installing the 20-013 on your window, but looking at your configuration I think one major issue would be the gap between the top and bottom sashes. Your top sash appears to have a lip at the bottom edge, and if that lip projects too far out then the 20-012 may not have enough clearance to stop the bottom sash.

To make things simple for you, the peg on the 20-013 projects from the housing by approximately 1/2". You'll have to check the gap between sashes to ensure that it's not over that; even a little under might be too much. Just something to keep in mind.