Mixing various spoke widths in a single wheel
Given the age of the wheel, you're going to continue to snap older spokes from time to time. Don't worry about the gauge of the replacement spoke. Assuming it's within the range of appropriate tension, as long as it pulls true there's not much to be concerned about. I have multiple wheels with some of the thinnest gauge spokes available (Sapim CX Rays) with straight gauge replacement spokes. No issues to report.