As a stop gap, snag an inexpensive ruler with millimeter markings.
Line it up to the bottom of the syringe barrel.
Use the lines to measure small increments.
Attempted 2.75 units tonight. Had to eyeball it to the best of my ability with the ruler. We will see how it works. Not sure I want to give her that tomorrow since we won't be home to watch her. I'll see how she does tonight.