Simon carded an opening seven-over-par 79 to tie for 10th, while Reto returned an 80 for a share of 112th at the Golden Ocola Golf and Equestrian Club in Florida.
Top ranked Stacy Lewis, Azahara Munoz and Jessica Korda managed to complete the first round before darkness fell and the failing light forced 20 players off the course.
The trio share the first round lead on six under 66.
Simon dropped shots at the first, third and sixth holes, but shaved a shot off the deficit with a birdie at the par-three fourth.
The Johannesburg professional bogeyed the 10th and 13th, and double-bogeys either side of a birdie at the par-three second saw her complete the back nine in 41 strokes.
Reto, who finished her first season on the LPGA Tour ranked seventh on the Rookie List, offset five bogeys and two double-bogeys with back-to-back birdies at the 10th and 11th.
Reigning Investec Cup champion Lee-Anne Pace gave the season-opener a miss.
The Pearl Valley golfer, who won the LPGA Blue Bay and ended the 2014 season with a 38th place ranking, would play the Ladies Masters at Royal Pines Resort in Australia from February 12 to 15.
She lines up alongside 2014 Ladies European Tour winner Charley Hull, three-time winner Laura Davies and defending champion Cheyenne Woods.