Ok, I'm going to come at this from the other side.
I no longer fancy my husband. There are reasons for that, a past history of wildly drunken and infantile behaviour and has been fantastically selfish over the years. He's overweight and did very little to look after himself. I have to throw away clothes with holes and rips in them and frequently have to tell him to make an effort, in the way that I still do for him.
We have talked and he's trying very hard to fix things but I'm scared those feelings may never come back. I don't want to leave, I do love him, we have fun together and he's NOW a good father and husband.
What I'm saying is that she may be just as concerned and worried about her feelings as you are. I know I'm terrified! I don't want someone else, don't want my marriage to end. If I could wave a wand and bring back those feelings I absolutely would. I didn't want my feelings to change, I just couldn't stop it.
Things being what they are I have no intention of stopping trying to fix things. It's a slow process but being honest with each other, and I mean REALLY honest is a good start. It may hurt to hear it in the beginning but burying the feelings or not talking about them is a road to nowhere.
Maybe start by taking the pressure off. Try to pull yourself back together a little. Tell her you appreciate her honesty and that you are hurt. Talk about what you can do to regain that lost intimacy, I don't just mean physical intimacy. Sex should be at the end of this road, don't force it and just start talking.