Career nanny here. This too shall pass! The baby won't be sleeping in your arms forever. Until then, snack as you go about your day. Of course you should be able to sit down for 10 minutes and eat a bit while baby is playing on the floor, but not for 30 minutes. There will be a time when you have much more free time during naps. Now, if MB doesn't want you washing dishes or tending to laundry while baby is awake, then you obviously cannot get those tasks accomplished and that is how I would handle it. If MB seems a little to wacky for you, search for a new position.

The woman has BIG problems. Get a new job. Trust me.