I was 10 when this movie came out, and my whole family loved it. Heidi was and still is one of my primary role models, and I can't imagine a better heroine for girls to pattern after.
She's kind, brave, selfless, strong, persistent, resourceful, self-reliant, and a competent, caring leader. She also demonstrates an unwavering confidence in her knowledge and skills, without being arrogant or derogating others.
This movie is a rare gem in that it celebrates and encourages those qualities in girls, along with values such as love for family and friends.
My only gripe would be that Charlie Sheen seems somewhat miscast as Peter. Disregarding his bizarre behavior in real life, his performance isn't bad, but his American accent seems out of place at times.
I concur with those who recommend the movie for children ages 10 and up. Some frightening and violent situations might be too scary for younger children.
Overall, a wonderful, beautiful movie with danger, adventure, excitement, love, and friendship. I would especially recommend it for girls.