Remote SSH for Mum

Crshbndct writes...

I have never used SSH. When I was working in IT, it was all Windows. My days of linux began after I quit that.

So my question:
I would like to be able to SSH into my mum's computer so as to be able to do things like run updates, fix settings for her etc.

Both her computer and Mine run Arch linux.

How do I do this?

Thanks