@Allan, seems to be getting a bit of a habit of yours jumping in on my posts, you are here to moderate not tell me perfectly good advice is wrong. I answered the question he asked - which was would the version of Office that the laptop came with just 'sit in the background'
And I answered the second question which was 'will it uninstall the older version automatically', which is yes, so they don't need to worry about removal
Also it may be that the version she bought has less features in it, or be Microsoft 365 which is cloud based, and some people prefer everything to be local. If you tell them just outright to uninstall it before trying the new one, they lose the possibility of going back to the original.