A solution and the process by which the solution was found. Solving my own question.
TLDR: For those with a touchpad (laptop) and no mouse to increase or decrease font size on a Windows laptop. You may discover that the usual "Ctl and +" also "Ctl and -" shortcut keys do not work. Instead, you need to perform finger acrobatics.
Solution: Press Ctl and hold while simulating the mouse wheel scroll.
A mouse wheel scroll is simulated by using two fingers and dragging them from top to bottom or from bottom to top on the touchpad on a Windows laptop.
Zoom Out - Make Font Smaller: Ctl with two-finger bottom to top
Zoom In - Make Font Bigger: Ctl with two-finger top to bottomRequest for Developer: Please add in the standard "Ctl and +" also "Ctl and -" as shortcuts. This is quite a lot of legwork to discover a font zoom. And using gestures on a touchpad is quite clumsy.
Clues collected notes:
Shortcut menu shows I could change the font size.. if I only had a "MWheel" (Mouse Wheel). I don't

Google shows me that in Linux I can use finger gestures to simulate a mouse wheel scroll. I am not in Linux, and I hate the awkwardness of gestures (I use shortcut buttons for everything). However, this does also work in Windows.
I hope that I never accidentally change the zoom function again by being sloppy in bed with my laptop. I especially hope I do not accidentally change this function when I disappear into the mountains to write in a place where there is no internet access to remember how to do this. :)