I am a Canadian actress who was raised in another country and in one of my younger roles that is reversed.
Don’t know, Jessica Lowndes?
No, really, I didn’t understand the “role that is reversed” part 
No. By the role is reversed I mean that in real life she went from Canada to New Zealand. But in a movie which has a guy from a popular sitcom she goes from New Zealand to Canada.
Oh, I get it. Is it Anna Paquin?
Yes. It is Anna Paquin. The movie is Fly Away home .
I am a female music artist, I am very tall, am in my early 20’s, and don’t have a bad reputation.
Taylor Swift?
Yes. 
I’m not very good at this game.
Nice.
Clue 1: I’m a legendary actor who famously portrayed a man with an invisible friend.
I am completely clueless
Clue 1: I’m a legendary actor who famously portrayed a man with an invisible friend.
Clue 2: I had a long association with Alfred Hitchcock.
James Stewart?
Yes! 
Clue 1: I’m a legendary actor who famously portrayed a man with an invisible friend.
He starred in Harvey, a film about a man who befriends a pooka, an invisible spirit with the shape of a rabbit.
Clue 2: I had a long association with Alfred Hitchcock.
He was in four Hitchcock movies: Rope, Rear Window, The Man Who Knew Too Much and Vertigo.
She’s not on right now, so I guess I’ll do one.
I am an actress who has done a movie for DC and also some for Marvel.
Halle Berry?
Oh jeez. You took my guess!
No. Hint: I had my first [spoil]s-e-x scene[/spoil] in a DC movie.
Malin Akerman?
Can’t be Akerman. I already did her, she hasn’t been in any Marvel for what I remember and… She had lots of *** scenes before Watchmen.
Natalie Portman?
No. Another clue 
: the person who was in said scene had never had a s-e-x scene before either.