What matters is the measurement between the seams, not the seams themselves. Sew whatever seam allowance gives you the finished size you desire. You only need to worry about it if it's not wide enough to be a secure seam, and that's not going to happen with a commercially cut square.
Assuming they're supposed to be 4½" finished, take a ruler and measure that width in the center of the square. What's left over on each side will be the seam allowance with pinked edges. From that you'll get an idea of what you're aiming for. Make sense?