Two teenagers, a boy and a girl, come together at a forest regularly (after school I think) and they have a small item like a coin or looking glass that they look through to see weird creatures around them that they otherwise wouldn’t have seen. The boy has a younger sibling, a sister I believe. At the end of the movie the teenage girl is killed by the creatures and the boy gets to the scene to find police cars around her house. I think they had an argument of sorts so the girl went off to the forest alone before she got killed and the boy went after her, only to find she was dead.
Bridge to Terabithia. More or less. I am not sure you are remembering it right.
There was a Made-for-TV adaptation of Katherine Patterson’s YA novel in 1985, and a Disney feature in 2007. Both hew closely to the plot which you describe.
“The Spiderwick Chronicles”(2008)?
http://www.imdb.com/title/tt0416236/?ref_=tt_rec_tt
watched the trailer and it looked like an exact match.
Well maybe not exact, but towards the end of the trailer you can see them holding the ring up to their eye to see the creatures.
Yeah, the OP is really describing a “Bridge to Spiderwick” movie. Which does not exist.
Sounds like “Bridge to Terabithia”