I agree with Michelle. I know for me personally, and I think a lot of Chi Os, we write recs for women we have a personal 'real life' relationship with. Generally alums like to at least meet a woman and get to know a bit about her before considering rec writing.
I would check with the local Panhellenic alumnae association as they may h ave contacts. Also, tyr to check around with family friends, at church etc. And if you can find, let's say, a DG alum, ask her if she knows any Chi O alums. You'd be surprised how many of us mingle!