My front passenger side window is slower than the drivers side window to come back up. I think it's also started to judder slightly. It does go down fine.

Is this likely a motor issue, or some easier fix such as lubrication/WD40?

on my previous 2007 fiesta the passenger side seemed to struggle up compared to drivers side from when I got it at 5 months old and I sold it at 9 years old. I never did anything about it but I always assumed it was probably the glass being impeded in the slots it moves up and down in.  I might be tempted to spray some of the dashboard shine spray stuff in the window guides. I suspect it will make a difference. not sure if I would use wd40 as I don't think it is quite as suitable for rubber and similar parts ( and my wife would complain about the smell of wd40).