Meanwhile, it has also competed a separate deal, worth around £83.5 million, to acquire Newton Private Client from Ms Young's former employer to improve its reach in the wealth management scene.
SLI has appointed Ms Young, a director of the UK Sustainable Investment and Finance Association, as head of socially responsible investing (SRI) to replace Julie McDowell who recently retired.
With SLI having hired former analysts Rebecca Maclean of Trucost and Alix Chosson of Generali Investments as SRI managers, she will have a four-strong team as opposed to the duo who worked with Ms McDowell.
Ms Young said: "Standard Life Investments takes sustainable and responsible investment very seriously.
"The success that Standard Life Investments has enjoyed in attracting new SRI mandates clearly demonstrates the importance that both the company and its clients attach to SRI.
"Through our efforts I look forward to contributing to the development of the principles and standards of corporate responsibility."
The acquisition of Newton Private Client adds £5.5 bn to the assets of Standard Life Wealth, the Edinburgh investment giant's discretionary fund management business, thereby tripling its size. It will also bring 4500 more wealthy clients to the business and 130 employees at offices in Edinburgh, London, Birmingham, Bristol and Leeds.