"I feel like there's still a lot of golf to be played, and I feel like there's a lower number than what I've shot the last two days. Hopefully that's coming in the next two," she said.
Ko had birdied chances on the first six holes but failed to pick up any shots and then dropped a stroke at the seventh.
She picked up shots at 15 and 16 but knows she needs to improve her play on the front nine, where she's been one-over both days, to stand a chance.
"If I put myself in that better position and put less pressure going into the back nine, that's a big key for me the next two days.
"If you start holing putts, you know that you can hole them again and again.
"The big key for me is to go tomorrow and the next day and play those first few holes feeling confident with the putter."