I think she knows what the answer will be and is waiting for him to offer in exchange for something. She knows he prefers for everything to be his idea.
As to the moral dilemma, I think she would do it if she could absolutely be sure he would honor his end of the deal. But she would not order anyone else to do it. She could even get around the horrible "I have prostituted myself for my crew" factor by reminding herself that Q was a non corporeal being and at the end of the day she hasn't had sex with anything any more human than Michael Sullivan.