That machine must have nreathed a sigh of relief after being cleaned. I think she needs to clean every season, not just Spring. When I got my first computerized machine I cleaned it before every sewing session, not taking the plate off but at least cleaning where brush that came with machine could reach. I did not clean my regular machines that often. We learned how to clean our machines when I was in 7th grade (1952) Our teacher felt we should know how to treat our machine.