uhmmm... Sometimes women smell bad down there because of a possible infection or fungus, maybe even STDs. She should go to the gyn, I learned a bit by volunteering. On the other hand, it might be that you just don't like the smell, so just tell her to wash up or use flavored things on her. (completely shaven women are more prone to infections, and using a different pH of soap is not good for it either)
hop in the bath or shower with her and make it sexy with you both cleaning each other. than you can go to the bed and do it after you both are fresh and clean.
Take a wash.cloth ore put a liqueur on her p****
I had an ex who I'd tell to wash her vadg before she came over. I felt like such an ass but she needed it. I suggest you don't go down on her until the smell goes away. It's possible she doesn't know about hygiene. I have heard girls will develop a scent if they're f***ing multiple men. In my experience this is true. The girl I mentioned earlier was. She eventually entered a monogamous relationship, saw me after it ended and she smelled fine. Just throwing that possibility out there.