Someday she may decide to change cell phone numbers or we may get a new home number (or do away with it all together). However, all our friends will never know the difference because the number they dial or text to will stay the same.
It’s all done with Google Voice. Just about everybody should have a Google Voice account. When you sign up you can pick an available local phone number. You then configure the account to handle calls and texts as I described above.
Think of the advantages of this service for a church. You can customize voicemail based on who is calling, you can listen to voicemail as it's being entered and answer right then, you can customize what callers are forwarded to what phone(s), and much more.