Hey, just a heads up - you can easily install a profanity filter extension on just about any browser, mobile or otherwise. Here’s an example for Chrome:
https://chrome.google.com/webstore/detail/advanced-profanity-filter/piajkpdbaniagacofgklljacgjhefjeh
That way you don’t have to see stuff you don’t want to, but also don’t have to attempt to modify the way other people speak to suit your desires.
One other solution to throw into the ring - delete the contact and re-enter it as a “phone only” contact. That way it’s not connected to her Google services whatsoever.