I have several and quite honestly, I don't think anyone should be ruled out.
1. Her living situation was strange, to say the least. She lived with her husband Mike and two roommates Samantha and Donnie. The roommates are in a relationship, on and off, dabble in transgendering (I know this isn't a word), and have been "involved" with Cathy and her husband previously.
The roommates seem to have a particularly violent relationship. Frequent fighting and arguing, several occasions the cops have been called to the house. About a week or so after Cathy went missing, the couple got into a physical altercation and resulted in the male being placed in the psych ward. After spending a week there, he was released and returned home - only to get into another argument about two weeks later that resulted in Cathy's husband calling the police.
The night before Cathy went missing, they had a party at their house - Cathy, her husband, the roommates and a few other close friends. It's been reported that there was an argument between Cathy and Samantha but no one knows exactly what it was about, they just made sure it didn't turn physical. *If I'm standing close enough to an argument, to make sure it doesn't turn physical, I bet that I would be able to tell you what the fight was about.
I personally find it strange that in reality, that was the last actual confirmed day/night that Cathy was alive and well. (there are pictures that were uploaded to facebook from that party) According to her husband, she drank too much and was sick in bed the following day. Her mother tried to call but she didn't answer, aside from the husband, the only other people to see her that day are the roommates. The husband made a statement that when he returned home that evening, Samantha said that Cathy had just left the house. - Did something happen during or after the party? I'm not sure but I honestly feel like if there was foul play, it happened the day before she was reported missing. I think it's strange that the roommates and other friends from the party haven't been involved in finding Cathy. They don't post to the facebook page, they don't post on their personal accounts and they haven't been involved in any of the searches. According to Cathy's husband, both of the roommates act like nothing happened and as if Cathy isn't missing, stating they pretty much keep to themselves and don't mention her disappearance.
I've also wondered if she was just simply unhappy with her life and walked away? She doesn't have custody of her children, she has a history of drug abuse, her family has made claims that she was very unhappy with her marriage... but she wasn't employed, she was on a fixed income. She didn't take her purse/wallet, her phone, none of her clothing, she didn't drive or have a car - while it's possible, I don't think it's likely that she walked away.