@mystery-ak If she has an apartment in that district and can get mail there, she can represent that district, even though she has a huge house somewhere else. She could also live with someone in that district and get mail there, and represent that district.
This has happened in Texas many times. Let's say you are a representative in your district and redistricting happens and your house is no longer in that district. You get an apartment in the new district where you can get mail and you continue to be the representative of that district.
Let's say you own a big house, you can get mail there, you own a lake house in another state where you can get mail, and you live with your mother in another state part of the year and can get mail there. You must have a "physical address", not just a mail box. Now, where do you vote?
You can register to vote at any of those locations but only register at one.