Something tells me that Lois won't be pleased that Clark as the newbie ended up with a bigger story than her. Although who could have known that it would end like this?
The teenage girl must have been very desperate to do what she did. There are a few possible reasons I can think of.
A) Lex is behind this (just because I think Lex is behind every shady thing in Metropolis somehow)
B) The girl is in a similar situation as Clark was when he was younger
C) Someone broke the girl's heart. (This one is probably the most likely reason)
Let's find out if I am right with my assumptions.