Former DUP MP Ian Paisley previously told the he saw Donaldson “blindingly drunk” during a St Patrick’s trip to Washington.
However, Little-Pengelly said she did not see anything that made her think Donaldson was a hard drinker.
“I can say hand in my heart, I didn’t see anything that made me think that there were any issues in terms of problematic behaviour in regards to drinking or in terms of sexually inappropriate behaviour,” she added.
“If any politician was running around acting in that way, I think it would have been the talk of St Patrick’s in [Washington] DC amongst the many, many, people from Northern Ireland that go out there.”
Little-Pengelly said she finds it “astounding that people haven’t been talking about that for the last 20 years”.
She said Donaldson would have had a glass of wine at events but she never saw him drinking too much.
“On some of this other stuff, look, I don’t know whether some of these allegations are true or they’re not true.
“All I can say is that I never saw problematic drinking from Jeffrey Donaldson.
“If anything, Jeffrey Donaldson was somebody who seemed to work all of the time.”
The full Red Lines interview with Emma Little-Pengelly is available now on Sounds.