Help request for Focus gear issues

Hi there, sorry if this is the wrong place to post, I'm new here and just looking for some advice from anybody who can help.

My nephew has a ford focus (2002 I believe), with a clutch/gear issue, and there are no local garages open just now due to covid19, so he came to me for help, and I in turn come to this fine place. I am not a mechanic, so forgive me if I fail to explain the issue fully.

At the moment, he is unable to get the car into gear at all. The clutch pedal feels fine, there is fluid in the reservoir, and no noticeable leaks. However, he can shift the gearstick into all gear positions except reverse, even when the clutch isn't pressed, but with no actual engaging of gears, and no power. It's as if the clutch isn't releasing at all, although as I say, the pedal does not feel loose or spongy at all.

My first thought was to check and bleed the clutch fluid, but given the pedal feels fine I doubt it's air in the system. Next I guess it's the slave cylinder to check? As I say, no noticeable leaks or anything, but any advice as to out next steps would be greatly appreciated.