I really wished they'd tested them because of that. I'm unsure who did it.

Yeah, I'm like wtf too. I think it had something to do with her family.

I remembered that this was mentioned over on the A&E discussion boards, so I dug it up for you. Thought you might want to hear what Audrey says in her own words:
(from Dec. '06)
okay- okay- I knew this was gona come up- I truly don't know how ti explain this... I-when I was with girl- thought that I was a lesbian- but all I can say now is that while I was in Florida, I met someone who compleatly supported and accepted all I am-all I was and did all he could to keep my CLEAN and HAPPY- and I am- both of those now CLEAN and HAPPY- My family (and my MOM) love him dearly- and things couldn't be any more perfect than they are today- who knows - one day I might have kids.... its impossible for even me to explain- (I never knew this would happen but Im extatic that it did.... it happens- I duno....im on "my space if you look me up- search Audrey Withem- and you'll see us...lol

This whole story was disturbing..not because she got an intervention for heroin, I mean its amazing that she went through rehab to get off it, but .....throughout the original story and the follow up, her family refuses to acknowledge the fact that she is a lesbian, and also uses bible quotes..well, I grew up in a fundamental christian church and a lot of good people who were gay/lesbian/bi committed suicide or wound up in a bad way because of such bigotry...I cringed every time her father got to talk on camera, and the sisters too.....wow..........

No I believe it really was the roommates.