In downtown Inverness, sandwiched between the post office and Vladimir’s Czech Restaurant, sits the Law Offices of Dakota S. Whitney. With its inconspicuous beige siding and drawn blinds, it can be easy to miss. But inside, Ms. Whitney and the business’s founder, Martha Howard, a 79-year-old with no immediate plans to retire, are keeping West Marin’s estates and trusts in order.
Operating entirely on a word-of-mouth basis, the duo oversees hundreds of last wills…