I had a similar situation with my daughter. A friend of mine and her son was interested in my daughter. For different reason he was not what I wanted for my daughter and she was not interested either. I knew that if I said outright no they would be very hurt and insulted. I knew what my friends son was like in terms of personality and how frum he is so I told them we are looking for the opposite. That did the trick they stopped asking.
Then another friend came along with a son and they were interested in my daughter, I did not think this boy was for her either but I like the family very much and know many of his siblings so my daughter went out just because they where pushing it(in a nice way) and my daughter had no one else at the moment and they hit it off so well they got married and we are so happy with him. So you really dont know.