The stand-up was among a group of comediennes who have taken aim at Schumer this week (beg18Jan16) amid claims she has nabbed gags for her own shows - and for the script of her hit 2015 film.
The star denied the allegations on fellow comic Jim Norton's satellite radio show, and on Thursday, Pescatelli, apologised.
"I went too deep," she said. "It went too far, and for that I'm super apologetic. I probably should have just stayed out of it and kept my mouth shut. I shouldn't have accused somebody."
Pescatelli now accepts her old joke about dressing her boyfriend poorly, so no other woman is interested in him, is similar to a gag Schumer came up with for Trainwreck - but not necessarily the same.
Tammy has deleted her accusatory tweets.