Can she see the list of available wifi connections? And is it the same list you can see? That's the first thing to check.
I had a problem with my Firefox not being able to connect in McDs because it would not go to the Wayport access page, which is necessary before you can get internet access there. Firefox kept trying to connect to the page I had set as home. I finally opened another tab and googled "wayport connection" and got to the right page first, clicked the "accept conditions of use" or whatever box, and then it worked fine.
Often there is a similar "first page" requirement in RV parks & hotels. If she's not using the same browser or settings as you, that might explain the difference.