YANBU at all. I have a difficult relationship with my mother at the best of times, and she is the last person I'd want around before, during, or after birth. She came to stay for a few days after ds1 was born, 'to help', and it was just awful. I ended up waiting on her hand and foot, because she'd say things like 'I don't know how your kettle/oven/dishwasher works'.
She had a row with the the mw who tried to explain to her that she wasn't helping with my recovery one bit and perhaps she ought to go home, or atleast go out and give us some breathing space.
I spent the bulk of the time in our bedroom hiding from her and feeding ds (didn't feel comfortable trying to get to grips with all that around her), and felt like a prisoner in my own home. Dh kept going out on errands to get away from her too.
When she announced that she would be coming this time I put my foot down and said we'd like this to be a special family time for the first few days/weeks, whilst we found our feet. She had a big strop and sulked for a couple of weeks, but has had to go along with it.