Thats because she thinks the Humber Bridge is literally the only bridge that exists in the UKEspecially when she's pointing at the Queensferry Crossing/Forth Road Bridge which is like 5 minutes from Edinburgh on the train and is a pretty well known landmark, even outside of Scotland. It's clear from this video that Molly doesn't know a single thing about the UK and this kind of video would have been prime for her to learn more about it rather than trying to rush across the country in a day.
You can literally see Edinburgh castle behind them as the walk down the hill into the station but nothing. Instead we get a nice shot of Pret! Then she gets to Inverness and treats it like some foreign country. It's part of the UK so it's not that strange