Five months after the death of Microsoft co-founder Paul Allen, the billionaire’s sister is taking steps to put her own stamp on a family foundation thought to hold at least $750 million in assets.

Sources tell GeekWire that Jody Allen, co-founder of the Paul G. Allen Family Foundation, is bringing fresh blood to the charitable organization. Among the names being mentioned as potential additions to the foundation’s board or to an advisory panel are former Microsoft CEO Steve Ballmer and Nancy Peretsman, managing director of the New York investment bank Allen & Co.

Three sources discussed the transition on condition of anonymity because they were not authorized to discuss the matter publicly. No principals in the process — ranging from representatives of the foundation and the Allen family’s holding company, Vulcan Inc., to representatives of Ballmer and Peretsman — were willing to provide comment.

Changes in emphasis have already come to light in the form of downsizing for Vulcan’s Stratolaunch space venture, and organizational shifts at the Living Computers Museum + Labs, Seattle’s Cinerama Theater and Vulcan Inc. itself. Based on the reports from sources, the transition to the post-Paul era is likely to take months longer, if not years.

Most aspects of Paul Allen’s legacy are staying constant: For example, the research institutes that Paul Allen created — focusing on subjects ranging from neuroscience to cell science to artificial intelligence — are said to be on solid footing for years to come. That’s largely due to arrangements that Allen made before his death in October at the age of 65.

In the past, the family foundation was exclusively directed by Paul and Jody Allen and people who worked for them. Forms filed with the Internal Revenue Service in 2017 show the two Allens as the foundation’s sole directors. The organization’s officers and managers were all Vulcan executives, with the exception of assistant secretary Allen Israel, who was Paul Allen’s personal lawyer.

The same forms list the foundation’s net assets as $756 million, with $43.4 million paid out for charitable purposes during 2016.

The Paul G. Allen Family Foundation supports a wide range of charitable programs — including efforts to monitor climate change’s effects on glaciers, on the world’s oceans and on coral reefs. It backed the Great Elephant Census, which documented the species’ catastrophic decline in Africa, and is continuing to focus on employing high-tech tools for wildlife conservation.

Combating homelessness, promoting arts and culture, and encouraging health innovations are also part of the foundation’s portfolio. Last year, the foundation contributed $30 million to get a homeless resource center off the ground in Seattle’s Mount Baker neighborhood. It has a rich history of supporting research in bioscience. And just this week, it kicked off a challenge program aimed at boosting the fight against the Ebola virus.

Widening a family foundation’s circle of advisers is a classic phase of organizational evolution, particularly after a major transition like the death of a founder, said Benjamin White, an Atlanta-based estate attorney who specializes in family-based philanthropy but isn’t familiar with the Allen family’s detailed circumstances.

“If you want the foundation to continue for a very long time, you’ve got to get outsiders involved,” White told GeekWire. The shift suggests that the foundation could plot a future course distinct from that of Vulcan Inc.’s for-profit ventures.

Ballmer and Peretsman may not have a direct business relationship with Vulcan Inc., but they’re not total outsiders, either.

Peretsman worked with Paul Allen on a series of investment ventures going back more than two decades, including investments in Priceline and Charter Communications. She was named in Paul Allen’s last will and testament as an alternate personal representative in case Jody Allen couldn’t take on that role.

Ballmer, meanwhile, got to know Paul Allen during their time together at Microsoft. Allen had some harsh words for Ballmer in his 2011 autobiography “Idea Man,” but in the years that followed, the two billionaires became close friends.

When news of Paul Allen’s death broke last October, Ballmer was one of the first to pay tribute to him on Twitter. “Paul was a truly wonderful, bright and inspiring person — and a great friend,” he wrote. “I will miss him.”

In his post-Microsoft career, Ballmer built up years of expertise running his own family charity, the Ballmer Group, and getting involved in civic projects such as USAFacts. (Ballmer and USAFacts are partnering with GeekWire on a podcast and video series called “Numbers Geek.”) He even credits Paul Allen, who bought the Seattle Seahawks and Portland Trail Blazers, with getting him involved in the sports world through his $2 billion purchase of the Los Angeles Clippers.

“He used to yell at me, ‘Steve, you got to do it, it will fire you up,’ ” Ballmer recalled in a tweet. “That too changed my life for the better.”

If Ballmer takes on a role with the Paul G. Allen Family Foundation, he’ll be in a position to return his friend’s favor.