I don't see it as ironic that someone who votes for (or represents) Labour has, or wants to have 'nice things'. To me, it's perfectly understandable that people might want to make the country a better place for others, so that there is a meritocracy that gives everyone a chance to live as good a life as as possible. The sneering at 'champagne socialism' is, to me, very similar to 'politics of envy' - ie a meaningless cliche that saves people the bother of coming up with an argument.
I am not in favour of anyone having two houses, largely because I live in a part of the country where people have made enough simply by living in a house in London to buy up so much of our local villages which then die on their feet as a direct result. They often retire to our towns, too, crowing about how the place they bought for £30k years ago would buy the whole street in an area that they have pushed out of the reach of younger generations of locals unless they have parents willing and able to help them out (that's not reading the room!). Local children often can't get places in schools that have been attended by generations of their families as 'incomers' take the places. It is very bad for my blood pressure when the same 'incomers' moan about asylum seekers wanting a better life at the expense of 'the indigenous population' 
I don't care who buys second homes, as they kill villages whether it is Labour or Tory voters who occupy them for a few weeks a year, and I don't care who the landlords who buy up properties in towns vote for either. It is true that without landlords young people wouldn't have anywhere to live - that's why so-called 'market rents' are so extortionate.
As far as AR is concerned, IMO she is no better or worse than anyone else buying second homes. I assume she will pay the higher CT, as she should, so there's no more to be said, really. The system is, IMO wrong, but it is the system, and at least the current government has doubled CT as a deterrent, which is a step in the right direction if not as far as I would like to see it go.
If it turns out that AR has had insider knowledge of something coming in the next budget and got in beforehand, however, I will feel differently.