This turns the question into more of a legacy play and accentuates the positive."
First, let me reiterate that every young advisor (or young professional of any stripe) should have a ready answer to the "age" question. It's a legitimate concern for clients (or patients). Professionals get paid for their expert knowledge and experience; it's perfectly reasonable for people to wonder if a younger advisor has acquired enough experience and real-world knowledge in a few short years. To be accepted as a pro, they need to have convincing answer ready to go.
As for the legacy response, I'm of two minds. The multigenerational issue is increasingly on the minds of advisory clients these days, as many of them have passed retirement age, and started thinking about their own legacies. Not only are they concerned about who will continue providing for their financial needs should their advisor retire (or pass before they do), they also want their children and grandchildren to get sound financial advice as they take control of the family wealth. So, responding to a challenging question with a solution for those concerns is certainly a good way to turn a negative into a positive.
On the other hand, the "positive" aspect of this response is likely to be lost on an older client or prospective client, if the young advisor doesn't also address the experience issue: "It's great that a young advisor will be around for my grandchildren—hopefully by then, she'll know enough to give them good financial advice." If young advisors are going to use the "legacy response," to fully put the issue to rest, they need to combine it with some statement about why their knowledge and experience is exceptional for a young person: They started very young, work closely with a senior advisor, grew up in a family advisory business, taught financial planning at Kansas State, have law and accounting degrees, etc. The answer doesn't have to be long, but it should include personal qualifications that speak for themselves.