In her long, long Reign Her Majesty has seen her European Realms going sluggish for decades and even through never-seen lows in the middle of the 1970's: the Winter of Discontent comes to mind, or even the then unimaginable which became reality: the IMF had to bail out the United Kingdom because the Bank of England had to withdraw from the foreign exchange market, due to the totally collapsed Pound.
The entrance of the United Kingdom to the (then) European Community, the Single Market and the Customs Union has given the nation so much. Today's United Kingdom is a far cry from the impoverished state it was in. All this was achieved during the full membership of the largest economic bloc in the world. The UK owes a lot to the close-knit, border-free, EU-wide trade. I would say: Her Majesty knows her classics and she has not forgotten that 48% of her fellow British citizens, and the majority in three of her European Realms have voted to remain...
Three cheers for the Queen!