Hi! Your daughter will have a great time. As far as tickets I know you can buy them online in advance (up to the day before) for potential savings on the gate prices, depending on the day she's going. If it's a weekday she'll most likely save more. This offer is only on the French DLP website and you have to print the tickets out.
Whether she should do both parks really depends on her interests. The park hopper option is 15 euros extra.
There are various things that are different from WDW, like the Star Tours is the old version, the Space Mountain is very different, Big Thunder Mountain takes place on an island, Phantom Manor is a darker storyline, Tower of Terror is the DLR version, Pirates has a few extra effects, etc. I could go on about that. The entirely different attractions are as follows:
Snow White dark ride (not in WDW anymore...doesn't really count but whatevs)
Tanière du Dragon (animatronic dragon cave under the castle, pretty cool and no wait!)
Alice in Wonderland maze, though this can take a while so I wouldn't recommend it for her.
Indiana Jones coaster, though this is short and lame imo;
Crush's Coaster in the studios
Ratatouille in the studios
Animagique in the studios---stage show but I wouldn't recommend it for her
Cinémagique in the studios---this I might recommend
Toy Story Playland in studios---not very interesting unless she likes thrills, in which case she might like RC Racer.
The daily parade
The Halloween cavalcade will be going on while she's there
Disney Dreams! The nighttime spectacular every day at park closing; definitely don't miss this.
Plus some other little things like a cars version of teacups etc.
Yes there is a fast pass system. It's the "old" WDW system where you collect paper tickets for a certain return time.
Hope this helps! If you or your daughter have any questions feel free to ask!
Cruzinmaniac x
