After watching the whole series through in
Japanese, I did not notice any "sexual" type
material or any real violence.  No one actually
dies (their character dies and they have to
restart the game).  Some of the characters have
different genders in real life than what they
appear int he game (like Tsukasa).  But, they
really don't dig deep into that subject in order
to be inappropriate for kids.  The characters also
carry swords and weapons like in the video games.

I would say that the material may be a bit too old
for her as far as the complication of the story
line (lots of computer tec talk).  But, I
personally think it is among the most tame shows
in Japan and Cartoon Network tends to edit out a
lot of stuff whenever they air it on TV (except
for the evening shows) and definitely a lot less
tame than Sailor Moon!  Hope this helps answer
your question.

Star Phoenix