Ouch for the timings .... very tight. If my memory serves me correctly there is a Gatwick Connect service desk after border control, but wouldn't know if they do airside transfers directly. Sorry. However, having had a similar MCI at Stansted, and having missed my connection due to the late arrival of my first flight, do check if there's any 'help' from Norwegian and the airline taking her to ACE in case she's a misconnect .... such as rebooking her at no extra cost etc ... and of course having enough funds available in case she has to buy a new ticket or spend the night if she has to travel either later in the day or next day. Even if she's flying from the same terminal, gates can be a fair distance away if you're not an Olympic sprinter ... thinking of the 100-117 gates in North!