How scifi? What time period? How mature is too mature? Without that, here is what I can recommend as good scifi, but you may need to sift through the content of each to determine if your daughter is mature enough for some. I have marked ones I think may need special attention by you with a ¤ icon. This is because it may be too scary, violent, or have nudity. Ones particularly egregious I marked with §.
A recommendation with ¤ beside it may contain brief scenes of nudity or some violence, or may make sexual references/jokes/innuendo, while a recommendation with § may contain scenes that are disturbingly violent or with scenes depicting graphic nudity.
// LIVE ACTION
Forbidden Planet (the original black and white is best but the color version is okay too)
Star Wars (Episodes 1-6, in release order of 4,5,6,1,2,3)
Alien and Aliens §
Predator (the first one) §
2001 Space Odyssey
Star Trek The Next Generation (original series and Deep Space 9 were also pretty good)
Doctor Who (take your pick of any season except the most recent one was not very good)
The Last Starfighter
Robocop 1 and 2 (the original ones not the remake) §
Galaxy Quest ¤
Abyss ¤
Space Battleship Yamato (2010 release, its english dub is okay, I dont know how accurate it is to the anime but I thought it was entertaining)
Bionicle 1-3
Stargate ¤
// ANIMATED-ANIME
Neon Genesis Evangelion and the End of Evangelion movie (the 4 Rebuild movies are good as well!) §
Super Dimension Fortress Macross (Robotech is okay as well, the first part is effectivly unchanged from the original)
Titan A.E.
Treasure Planet
AKIRA §
Bubblegum Crisis ¤
Bubblegum Crash!
Full Metal Panic! (all seasons)
Space Dandy ¤
Saber Rider and the Star Sheriffs
Cowboy Bebop ¤
Dirty Pair ¤
Trigun (the original release, not the recent reboot) ¤