When Joseph Goodman (company owner and head honcho of the DCC RPG) started his quest to write a new RPG, he had a couple of key elements that he wanted to see. He wanted a game which was simple to play, he wanted a game which reflected the feel of the old Appendix N stories, and he wanted something with funky dice.
Back in '75 when I first started playing it was really hard to find decent dice other than standard d6's, but nowadays most game stores (and many bookstores like Barnes & Noble) carry standard polyhedral dice sets for gaming. DCC RPG takes that standard poly set and adds in a few more funky shapes, but you can simulate most of the unusual ones with a little imagination and the standard poly dice. Could he have designed a game to use percentile dice only? Sure, but that's not what he wanted.
By the way, giving both 5E and DCC a look is a good idea. Each game brings a different style to the table and it will be interesting to see which you (and your daughter) like the most. 5E is the best version of D&D (in my opinion) since the old 1E/2E days at TSR, but DCC is a lot simpler to play once you get over that "every spell has its own table" thing that seems to trouble some players.
_________________Marv / FinarvynDCC Minister of Propaganda
; Deputized 6/8/11
DCC RPG playtester 2011, C&C
since 2003, ADRP
Since 1993, OD&D
player since 1975
"The worthy GM never purposely kills players' PCs, He presents opportunities for the rash and unthinking players to do that all on their own."
-- Gary Gygax
"Don't ask me what you need to hit. Just roll the die and I will let you know!"
-- Dave Arneson