While i understand what the OP is trying to do, Revenue IMO may think that there is a speculative element in this case.
The second house has been bought in 2007, only to be used by
daughter in about 10 years time, and is rented in the meantime.. So one would raise the question as to why the house has been bought now and not in 10 yrs time when needed by daughter?
So IF (big if as i don't know) there were to be allowances in the legislation for OP's case, it will be invalided by the renting between acquisition and use.