Yes, she is annoying me too. In fact both couples are to some extent.
I think, what it is, is that they all seem to want perfection regarding location, house, flat itself when they are first time buyers.
Back in the day they would be looking at things at the bottom of the ladder, but now they aspire to the forever, perfect home that others would take years and multiple house moves to get.
It could be that homes at the bottom of the ladder are snapped up by buy to let investors and they have no choice to look at more expensive homes.
However, they always seem nowadays to be so ungrateful and have snide comments about some really lovely homes. Saying that a brand new modern looking kitchen diner is "totally not to my taste and needs ripping out immediately" was infuriating to hear.
I know they are spending a lot of money, but their expectations are ridiculously high and it spoils what used to be a good programme.