Descriptive protag(s) in a logline is always good. The second half reads awakward. It's in the passive voice. Also, I'm not sure how quickly they find out the spirit is their son who turns out to be alive, but it sounds like a sizable revelation that may be better suited for just the script and just hinted at in the logline, unless there are more/bigger revelations to come.
I'll give the firs ten a look and see where it takes me.