Hidden address bar

[Brakes to Park]

My silver surfer mother has allowed my even silverer stepfather to somehow hide the address bar. The obvious solution to this problem would be :

View/Toolbars/Address Bar and obviously make sure that address bar option is ticked. Unfortunately when she does this the address bar remains hidden. She has tried resizing the page and that doesn't show the address bar either.

Any ideas???

[What_does_this_button_do?]

Press F11

[Brakes to Park]

Many thanks.