While I rate this film age appropriate for children aged 7+, I'm thinking more in terms of boys, whereas girls younger than 10 may feel uncomfortable about body image due to the Furies' indigenous attire which consists of bare clad bodies covered by loin clothes and large ornamented necklaces concealing small breasts. However, these 'alien' bodies are blue and painted with illuminated makeup that they do not resemble humans, plus are androgyne in body type, so males and females are distinguished by the make up and jewelry worn.
While boys are likely to be accepting of the National Geographic body image, conversely, there is a mating scene in a gorgeous landscape where the hero and heroine stand under a sacred tree to wed by a kiss. They remain in their indigenous attire and while standing, embrace one another with loving eyes to gently kiss and seal their hearts. No overt Hollywood-like sexual conduct. Girls may be more comfortable during this moment than boys under age 10. My 7 year son old scrunched his eyes and said "yuch," and I think this was the consensus for school aged boys. Do take care to not leave the theatre for popcorn during this mating scene, as I did with my son, because I was told by friends who remained seated that the scene lasted only for that kiss so we missed the pivotal arc of the film which immediately followed. Just know that when the kissing scene under the sacred tree happens, it's brief and you may remain in your seat to distract your kid for that half minute.
The only issue I would have with this film is the soldier-like foul language spoken by military personnel and a woman lead scientist who is a smoker. When such language was heard, I said to my son "that's some mouth on that soldier" and he replied "he needs better manners" so in a way the bad language on screen was a 'teachable moment.'
Other teachable moments are the many subtexts on ethics. The film's themes offer discussions with your children about genocide, deforestation, commercial greed, fairness, appreciation for the sacred, what is consciousness, what is beautiful... I feel that in bringing my son to this film, which is also stunning to watch, my son and I went home with much to talk about that's going on the world presently plus history (Trail of Tears, crisis of the rain forests, kindness to animals). There is also a good message about living humanely and respecting all living creatures, especially one another.