Traveling with Grandchildren

My mother will be taking my daughter on a trip to Disneyworld in a few weeks, so I will need to write a permission letter for travel and medical reasons. Is there specific wording I should use? Should it be notarized? I’ve searched Google, and while many sites say you should have a letter, none say what should be in it.

Any advice most appreciated.

You should be able to obtain a temporary transfer of guardianship form letter from any legal bookstore or paralegal office for around $5. I also found many on the web (search gaurdianship transfer letter on Google) but they will cost $12 to $20. I do paralegal work as a hobby for fun and no profit. But I will not use this forum for business purposes as I feel that would be unethical.