The defending champion struggled with the speed of the greens on the Fidra Links, carding a two-over-par 74 to sit seven shots off the lead.
“I didn’t putt well,” said Matthew, who won the event by ten shots at the same venue last year. “I couldn’t get the pace of them and kept coming up short all the time, which was frustrating.
“You would think that I would have started to hit them a bit harder after that happened for a few holes, but it was the same throughout.”
Matthew, who is based at Archerfield Links, reckoned her game in general had been satisfactory apart from a couple of slack shots.
One such error cost her a double-bogey at the ninth, where her tee shot found water.
It was suggested to the North Berwick woman that she had perhaps been a bit rusty, having last played competitively in the Kraft Nabisco Championship in California early last month.
“I don’t think so,” she replied. “I just made a couple of silly mistakes. But at least I finished with a birdie.”
Matthew started her second round tied at 35th, safely within the cut in the 54-hole event.
But Musselburgh’s Vikki Laing had work to do after she opened with a 76 to find herself right on the line.
Laing was out in 37, one-over, but dropped four shots in seven holes before matching Matthew’s last-hole birdie.
Leader Anne-Lise Caudal made her score by racing to the turn in a best-of-the-day 32 — four-under par.