Hi there, Erika!
In
Tinker Bell's Magical Nook (located in Adventureland in the heart of the
Magic Kingdom), she will find Tinker Bell and friends; the linked official Parks blog entry does say that "One of Miss Bell’s friends, Vidia, Rosetta, Silvermist,
Fawn, Iridessa, and Terrence also may stop by to join in on the fun" (emphasis mine).
You might want to check with a Cast Member in Guest Relations at the Magic Kingdom to find out if Fawn is, in fact, fluttering through the Home Tree that day.
At
Epcot, however, Fawn seems to be the fairy that just can't get caught! While your daughter will be able to meet Tinker Bell, Vidia, Rosetta, and Terrence at Epcot's Pixie Hollow, Fawn is not presently on the character lineup, but that does not mean that she is destined to remain in the Magic Kingdom. Again, feel free to check in with your Guest Relations Cast Members to find out if she is about.
Hoping you and your daughter get to find Fawn on your next adventure!
See you later, celebrator,
-Deborah B.