NikL,
I was in a similar situation. My wife had her mother in our home after a stroke, and it was very tough on her. We did have a few visits from Elders to encourage her. Even a CO (but he was one of the very few good ones). I think your wife is sending strong hints that you decline. Listen to her.
As others have suggested, just thank them for the interest shown, and let them know that you will get back to them 'soon'.