The ex-DTM racer, who is a Williams development driver and previously tested a 2011 car at Silverstone last October, had aimed to break the 1m35s barrier and ended up with time less than a tenth away.
This compared well to fellow Williams tester Daniel Juncadella, who logged a time of 1m34.631s on Wednesday morning.
"I had a fantastic chance from the team, they took the chance to put me in the car today," said Wolff.
"Many people said they were crazy, [asking] why were they wasting a day on me and they took that chance.
"I was happy that I could do a good job and pay them back for that.
"I saw what he [Juncadella] had done and the team were quite impressed with that so that was my goal.
"I was only four-tenths off a Formula 3 European champion, the guy who is rated as an up-and-coming young star, for me that was really important."
Wolff's lap came on her fourth lap on a run on medium rubber, meaning that she is confident her headline pace would have been stronger given another run on fresh tyres.
"With the medium tyre, it's quite difficult to get the fronts and the rears in at the same time," she said.
"I struggled quite a bit with the fronts on my first flying lap and then when the fronts were in the rears were already starting to go.
"I did my quickest lap on the fourth lap, which is not how to get the best out of a tyre.
"There was more potential there, definitely."
Wolff insists that she was always confident she had the ability to deliver a strong performance in the test.
She added that the lack of competitive machinery in the DTM, where she competed for Mercedes from 2006-12 with a best finish of seventh, has possibly led to people writing her off.
"I always said I wouldn't be doing this if I didn't think it was possible," she said. "I believe in myself.
"After such a tough end to my DTM career, many people presumed that I was just always at the back and just wasn't quick enough.
"Today can show possibly that is an unfair judgement.
"DTM is difficult to get in the right position to be in a winning car and I was never in that position, so for me [today] was about going out there and showing what I can do."