It is most likely part of her business succession planning. I am the only equity owner of my firm, which I had run for the last decade. I have 6 employed solicitors and 5 more paralegal/support staff.
Law firms are pretty difficult to value, and at 48 I have had to start thinking about my succession planning. I have a key employee who will become an owner of about 20% from the start of the next financial year - this allows me to secure her continued involvement and gives me the start of an exit strategy. I plan on bringing on a couple more over the next 5 years. The addition of new owners also gives me more comfort in expanding the business, as I can share the supervisory load among people with skin in the game, and when it comes to time for me to retire I will have ready made buyers for my remaining stake.