My niece was born with a partial second thumb, so when she was old enough she had surgery to have it removed. She was a real trooper and did very well! You would never know she had ever had it, no scar at all!

I used Anna Aspnes Designs ArtsyLayered Template No. 127
https://www.oscraps.com/shop/Artsy-Layered-Template-No.-127.html
Charlese Creations - Care For You
https://www.oscraps.com/shop/Care-For-You-Kit.html