The small hands thing is a myth.. The big hand thing is a myth... The missing digit thing, while not a myth, guitar players learn to work through it.. It's a matter of acquiring flexibility and muscle memory, a desire to overcome.. I remember see a you tube video where the guitarist used his toes. Fretting and picking. I'll see if I can find the video. Keep at it..
So practice, practice, practices.. That's the key.
Have you gone through the lesson fundamental... I believe the 1-2-3 fingers method is still used here..? That's what they show in the Ultimate Chord Finder "top right corner" "red banner" "7 icons" middle one..
Hope this helps you out..
Here's the link of toe guitarist
https://www.youtube.com/watch?v=fqoEZaCd7hU