"When I saw them together, I thought she's too good for him," he said.
All of Chapman's friends reached by ABC News asked not to be publicly named out of fear of possible retaliation by Russian interests.
A local realtor who met Chapman outside her downtown Manhattan apartment a week and a half ago said he first approached her because of her stunning looks, but then was drawn to the business acumen she emphasized.
"She said she had started a company – some crazy search engine that basically stole all the leads in real estate." He said. "She had data technology that combined every single real estate database that you could think of into one. She had a way to get people's information. She was in the business of selling leads."
Still, he said, something was suspicious when Chapman brought him to a business meeting with her team on the terrace of her apartment.
"They were all a joke, the people who were working with her," he said. "Something didn't add up right, but I just wanted to see if she could deliver. She knew nothing about the market."
Arthur Welt, a 36-year-old Russian journalist living in Moscow who first met Chapman in 2008 at a start-up conference, said the idea that Chapman is a spy is "nonsense."
"She was very professional in the real estate market," Welt said. "Startup founders don't have time, especially not for espionage."
One trait many friends in New York noticed of Chapman, however, was her "sweet" demeanor, which has left them all reeling in shock as Chapman remains jailed without bond.
"She was one of the sweetest ladies I've ever met," an acquaintance said. "Everything about her was so sincere, so sweet, no tricks up her sleeve. I don't think she had a bad bone in her body, and if she did then somebody was putting them up to it."
Another friend who had been close with Chapman since meeting her on a ferry nine months ago, said their shared social group can't get over what Chapman stands accused of.
"Never have I ever thought there was something like this happening with her, that's just crazy to me," said the friend, a former party promoter who said Chapman frequented his events. "I'm getting a million texts and emails from everyone. We're just shocked."
Chapman's attorney Robert Baum said, "The government's case is very thin against Ms. Chapman. There is no allegation that she ever met face to face with any governmentt official. No allegation despite constant surveillange that she ever delivered anything to anyone or received any money."
Eleven accused spies have been arrested this week in the bust, the result of a multi-year investigation, the Department of Justice said.
Four couples living in the U.S. under assumed false identities - Richard and Cynthia Murphy of New Jersey, Donald Howard Heathfield and Tracey Lee Ann Foley of Boston, Massachusetts, Michael Zottoli and Patricia Mills of Arlington, Virginia, and Juan Lazaro and Vicky Pelaez of Yonkers, New York - are charged as charged with conspiring to act as unregistered agents of Russia and conspiracy to commit money laundering.
Chapman and another defendant, Mikhail Semenko, were also arrested Sunday for allegedly aiding in the same suspected Russian spy ring.