this is a movie from the 80's where there is a little girl with a 
cartoon kangaroo as her freind  this movie has real actors and live
movie with a cartoon
kangaroo throughout the movie,  i believe I saw the movie in toronto
around 1985.

I vaguely remember a movie with a girl and a kangaroo. The girl ate
magic red or green roots to grow large and small. A quick Google
search for [kangaroo movie root] says this movie is "Dot and Keeto."

  Dot and Keeto (1986)
  http://www.imdb.com/title/tt0090960/

Reading more about it, I'm not sure if it's the same as the movie
you're thinking of. The kangroo may have been a minor character, and
the girl is "live" in the beginning and animated for most of the
movie.

I also remember this film from my childhood, but the one I'm thinking
was made a bit earlier (1977) called 'Dot and the Kangaroo'.
This was the first of a series of 'straight to video' kids releases
here in Australia. 'Dot and the Kangaroo' was the orginal.

Other titles include:
Dot and Keeto (1986)
Dot and the Bunny (1984)
 aka "Dot and the Rabbit" - Australia (working title)
Dot and the Koala (1985)
Dot and the Smugglers (1987)
 aka "Dot and the Bunyip"
Dot and the Whale (1986)
Around the World with Dot (1982)
 aka "Dot & Santa Claus" - UK (video title)

You can find all of these on imdb.com
Title search 'Dot and"

It should be noted that the "Dot and the Kangaroo" movie has already
been suggested:

http://www.answers.google.com/answers/threadview?id=586281

The Dot and the Kangaroo films (based on books) were entirely animated:
http://www.angelfire.com/de/isis/dot.html

I'm afraid I haven't been able to find any film that features a real
little girl with a cartoon kangaroo.