She is legally obliged to list the commercial address of the company. If that's your home address, as it often is for small freelancer businesses, then she's right.
I'd go the practical route and have a Panikschloss installed. It should be as simple as exchanging the Schließzylinder. Guckst du. https://www.amazon.de/dp/B09BTWTK9Q?tag=h_oo_2-21&linkCode=ogi&th=1&psc=1
This is what Princeton says about it:
Maternal language: Noun - one's native language; the language learned by children and passed from one generation to the next.
I'd say OP's maternal language is in fact English.