Does the girl have genuine feelings for you? Or was the idea of a "match" planted into her head by her concerned parents? Sometimes the suggestions of others, especially parents, can put ideas in our heads that we never gave much serious thought to before. I'm assuming that since you so "BLUNTLY" told her that you're not interested, that this implies you both are able to have open communication. Straightforward communication is an integral part of a friendship, CM. If you still value the friendship, I would suggest that you, once again, talk to this girl about the issue NICELY.
"I just wanted to say thank you for inviting me over for a lovely meal. I appreciate your consideration. I'm a bit concerned because you haven't seemed your usual comfortable self lately. You seem a bit tense. And I hope that it's not about the proposition that came up earlier. I enjoy the friendship we have and I'm sorry if I've unknowingly given the impression that it was anything more than that. And I'm being honest with you because I don't want to unknowingly lead you on. It it's difficult for you to remain friends or if you need some time away from me, I understand."
She might be hurt, but she'll appreciate the honesty. Most people (men and women) think of the other person as a "coward" or "jerk" when they reject through a sudden cold shoulder that came without warning. InshaAallah she'll move one. Pray that she finds someone amazing. Even rejection, as unpleasant as the task seems, can be done with dignity or decency.