A New York City investment advisory firm ultimately owned by global venture Aon plc has agreed to acquire Walden Wealth Partners LLC, an all-women registered investment adviser in Beachwood, Ohio, for an undisclosed sum. Wealthspire Advisors LLC, the New York acquirer, noted in a statement on the deal that Walden's founders, Karin Maloney Stifler and Sarah Hannibal, both have decades of experience serving multigenerational clients. The deal would add about $420 million in assets under management…