YA Science Fiction book about children crash landing on a forest/jungle planet.

I am trying to find a book I read in the late 1990s. It was written for young adults and I'd consider it science fiction. The name had some similarity to "Star Child" or "Star Children" I think. The premise from what I remember involved two kids, possible siblings, who are exploring some sort of forest/jungle planet after possibly surviving the crash landing of their ship. My memory is a little fuzzy so I may be misremembering some of the details.

I remember a scene where the children are on the branches of a massive tree, and there are some sort of friendly alien creatures that maybe lived in the trees.

I am pretty sure the cover of the book was mostly dark, maybe black, with some sort of "egg" or crashed spaceship.

Thank you!