The board member doesn't need to have amnesia. While he/she told OP she could have a roommate, he/she qualified this by also saying that OP could not charge rent to said roommate.*
(There are plenty of possible situations where OP might get a roommate and not charge rent - if she invites her child/parent/sibling/BF to come live with her, for example. I have a friend who invited her sister to live with her for six months after sister went through an incredibly abusive spousal relationship and acrimonious divorce - violence and stalking etc., the whole nine yards - so that sister could get a job, a place of her own, and back on her feet again. This was in no way a landlord-tenant relationship. I think OP's condo board is trying to allow the residents to have that sort of freedom, while at the same time preventing a whole lot of stranger tenants from constantly moving in/out of the building.)
*And this is the core of OP's problem. The only reason she wants a roommate is so that she can charge rent, and because this would be in violation of the condo by-laws, she's SOL unless she's willing to be responsible for whatever penalties the board levies upon her for violating the by-laws.

