B.W.
Hi! I actually had a very similar situation with my daughter's thumb. The way you describe her fingers is what my daughter's thumb looked like, but she was under one year. We put a bandaid on and taped it all around (it ended up being quite large!) so she couldn't suck on it. She mostly only sucked her thumb when sleeping so it caused a little problem with her falling asleep for a couple nights but she got over it in what seemed to me a relatively short time. I think you should continue what you're doing - maybe tape it up a little better (we used some first aid tape) and leave it that way - one or both fingers. Good luck!