This is a problem with you - you have not established clear boundaries with your wife. My wife works from home and I know to leave her alone. She informs me of which calls are important so I take the dogs and keep them in the bedroom with me so that they are quiet if the doorbell rings, etc. Since I work from home too but I'm more flexible I make lunch at the time she agreed to have it (according to her outlook calendar for the day). I only start complaining when I see it's 7pm and she's still working... or when she allows herself only 10 minutes for lunch, but I know she won't change. But tell me - why doesn't your wife work? That way she'd leave you alone.
I've suggested working to her a number of times. When the kids were younger it made sense for her to stay at home - before they started school the day care costs would have been more than her salary, but she could work during the school day now.
I have to say though that apart from when I try to work at home she looks after the house and the kids well, has a meal ready for me when I get home and is always attentive - which is nice.