Parsing

Currently doing my assignment on Language Description. Parsing is very confusing to me =.="
Last Monday, I was asking my lecturer how to parsing this sentence :

"One night, Wendy woke to find a strange boy sitting on the floor who was crying."


I still don't get it after all the explanation. Totally confusing to me.

Here's my example PARSING of my coursework :
(I hope this one is correct or it will be embarrassing >.<  )