Serving at a set and 2-0 down in her semi-final, the unseeded Israeli had to wave her arms several times before the girl snapped back to attention and threw her a ball.
The pink-clad Peer lost that service game and her next before slumping to a 6-3, 6-0 defeat, her fifth in five matches against the American fourth seed, who will play Czech Lucie Safarova or Aravane Rezai of France in Sunday's final.
"With Venus I always have trouble and she always dominates from the beginning of the match and the beginning of the points," Peer told a news conference after her opponent had reeled off nine straight games to seal victory.
"I was struggling with my serve and she was just a little bit too powerful for me," added the 23-year-old.
Asked about Peer, Williams said: "She's just a tenacious player, really talented and never say die spirit. So I was ready for that and I just seemed to be able to find the corners," she added.
Williams plays in the doubles final with her sister Serena against Gisela Dulko and Flavia Pennetta later on Saturday and is projected to regain the number two spot behind Serena in the singles rankings when they are updated on Monday.
It will be the first time since May 2003 that the siblings, who have won 19 Grand Slam singles titles between them, have been one and two since May 2003.
Venus Williams beats Peer to reach Dubai final
Sania to play Rezai in 1st round of Aus Open
Sania's 1st round match rescheduled
Sharapova on course
Pennetta knocks out third seed Jankovic