Michael Hertz at Lucco, Brown, Threlkeld & Dawson can assist you with the documents that you need, such as powers of attorney for health care, property and wills.
The linked Wall Street Journal article (may be behind a paywall) highlights the issue that parents and their children face when they turn 18.
https://www.wsj.com/articles/documents-you-need-when-a-child-turns-18-1511972303