Hi, Dianna!
Congratulations on considering a Disney cruise -- my family and I have never regretted any moment or cent spent on a Disney Cruise Line vacation. They are great investments in forever family memories!
As long as you are traveling with your daughter and she has a valid US passport, you should have no problems traveling with Disney Cruise Line. However, as a caveat, please make sure you are aware of the border regulations for the countries you visit on your Disney cruise. For instance, this summer when we were traveling to Alaska by way of Vancouver, BC -- Canada requires that parental consent be given by the other parent if traveling with only one parent. Therefore, to be on the safe side, you might want to make arrangements for this in case it's an issue.
For complete and up-to-date international travel information, it's always a good idea to check with the
US Department of State's website, too. I hope this helps, and be sure to let me know if you think of more questions.
Have a wonderful day and a magical vacation. Bon voyage!
Andi