As far as I understand, the parents were contacted by some type of congressperson. There has been no suggestion that the parents were contacting congress because of this matter. I'm not sure if their boy told them about the e-mails, although we do know he fowarded them to others. We don't know if he was particularly upset or bothered as he didn't make an official report. Maybe he just thought it was weird and creepy and sent it to others to show them, "Check out this weird, creepy guy! LOL!!"
If the parents were unaware of the matter until contacted and they were disinclined to do anything. I don't see that as "being concerned about Foley's e-mail".
Thought some might want to take another look at this old post:
http://www.freerepublic.com/focus/f-news/935088/posts
It is a post from 2003 when Foley dropped out of the senate race amid rumors that he was gay. Seems someone in his own office spread the rumors according to this article(which is no longer available).
"Rodney Alexander brought to my attention the existence of e-mails between Mark Foley and a former page of Mr. Alexander's. Despite the fact that I had not seen the e-mails in question, and Mr. Alexander told me that the parents didn't want the matter pursued, I told the Speaker of the conversation Mr. Alexander had with me.
http://hotlineblog.nationaljournal.com/archives/2006/09/tom_reynolds_st.html