There are lots of websites for platonic relationships. Using okcupid is telling. LOL @ the thought of a girl using Okcupid to meet friends, when 90% of the guys there are looking for sex, and the girl's going to get bombarded with a plethora of pervy messages. Yeah, that's just an awesome way to find a platonic male partner.
People (usually girls) will often refuse to admit that they are using OKC for dating. I've met countless girls off OKC who insisted that they were just looking for friends. But it was BS. Its fine, it's a natural defense. No one wants to advertise they are single and looking. This goes for guys too, by the way. Guys are on there to get laid because, well, guys are always looking to get laid. I do think some girls are on there just for attention, but if they are single, at the end of the day, they are going to be open to meeting people that catch their eye.
You came on here for input and I told you what I thought. You can take it or leave it. No need to get defensive. That's why the first question I asked was whether you had met her or not. If you had already met her and hung out with her, then it'd be more defensible (though still a bad idea IMO). This isn't just directed at you, since it seems like its a moot point in your case anyway, but at anyone else who might be thinking along similar lines.