The way she acted when she first told him about it seemed like she was hiding something. Why so against him staying if she's that scared?
The way she just turned around and left after he said "i'll get you out of here" was weird. No thank you? No hug?
The way she was adamant about the chipped plaster being new was weird.
Either way it probably doesn't matter since it doesn't seem like he's going to confront her about it, unless she does something like that again. I just don't think it's crazy to not take her actions at face value.
I agree, there's too many clues to suggest she's manipulating him. A scene last season alluded to the same thing, that she was using sympathy to get money.
It doesn't fit with Mike's character at all though, because he'd surely see it coming. We've been led to believe he's very sharp, so to be fooled by his daughter-in-law would be odd. I think they're deliberately trying to confuse the issue for some sort of payoff later.