My mom still uses OpenOffice at her job (municipality), and honestly they haven't really felt a huge difference, they still get their work done like before, but heck there were some training to do as they were switching. I suspect at this point they would need the same training just to get back to word etc.
> OpenOffice
That has not had an actual release for something like 12 years, and has had known unaddressed security vulnerabilities for... what is it now, a year? Two years?
That is a dead project. Please Tell your mom to tell her bosses they really should switch to LibreOffice. Which is simply the continued development of the same thing. The municipality can write the Document Foundation and ask for assistance:
https://thedocumentfoundation.org/
and there are of course commercial companies which do LO transitions too.