M.R.
Whenever I've had one I soak the toe, clean under the nail and lift it up and tuck a small piece of cotton ball underneath (torn off, just enough to keep it lifted). This helps the toenail grow out in the right place and keeps stuff from getting buried in there. I know my mom used to do that when we were kids and she is a nurse, but I'm not sure if you could get your toddler to let you do that.