Personally, a respectful minutes silence at games this weekend including City v Spurs(and Black armbands) will more than suffice I believe. The impact on a nation that is already struggling if there are12 days of mourning would be very damaging. Businesses on their knees could shut and lose more money, staff already struggling to pay bills would not be paid.
Obviously, you feel for anyone's family,/friends when someone close dies and I have nothing against her as a person.
There's nothing wrong with feeling sad if celebrities you don't know die (I thought itvwas sad when Taylor Hawkins died)
However,the whole concept of the Royal Family and the amount of money that Is handed out to them when so many are struggling is very devisive anyway. Potential mass disruption to people's work and leisure time (so important in grim times,)would only add to this.