2013 Toyota Prius pax seat air bag light stays off and is intermittent when my 90 pound wife sits in it..HELP

Hello, I'm so sorry. The problem is - these seats are calibrated to prevent children from being harmed in the front seat. My suggestion would be to ensure she is sitting back far enough in the seat to engage the sensors as they are. Besides weight, positioning is important. I hear your concern, but there really isn't any fault occurring -- it's unfortunate circumstance. Check with your local dealer for further advice, but I'm not sure there is any.