A lot more info is needed here. How many days a week are you working? 5, 6, 7? How is the WX at the school? Are airplanes available and not completely filled?

I flew for a larger 141 with decent WX most of the time. There is no hard and fast rule. One month I billed just about 130 hours flight time and the next month it was just over 60. WX, aircraft, students progress are all factors. I think I had 7 or 8 days off when I flew 130 and 3 of those were WX days. Technically you could fly up to 240 hours if you had everything perfect. I would never wish that on anyone because I would imagine that the individual would either be needing to live at the airport or would be highly fatigued. At a larger 141 a good guess on average would be about 4 hours 4 days a week. In the summer bump that up to 4 hours 5 or 6 days a week. These numbers are only if you have good aircraft availability and students that need to learn.