@jollajo /e/OS has built-in forked davx, calls it “accountmanager”. No need to install it again.
as GabrielT says, create a calendar and copy the subscription link that you send your wife. Google Calendar (web) should be able to subscribe to this, in doubt she needs icsx5. Will look like this:
https://murena.io/remote.php/dav/public-calendars/xyz?export
It’s not automated to update new calendars sadly. At the end of [HOWTO] Use the Calendar App under “Limitations” is a screenshot how to fetch the newly created calendar on your own device. You could also just choose to share your pre-existing personal calendar.
If your wife is using the Samsung Calendar app to interface with a Google Account, those can create external subscribe-able .ics / icalendar urls too. Looks like this:
This link explains how to use the Web Calendar Manager on your side.
In the end you subscribe to your calendars each read-only.