My mom has fluid around her lungs and dr's did a tap and draw and they want to do a procedure called scarring. Would you recommend?

The term Sclerosing. This causes inflammation and fibrosis or in other words scarring. The hope being it would keep the space where the fluid fills up in from existing and no long be able to accumulate fluid there.
Yes. Generally only procedure to prevent fluid from coming back. Does your mom have cancer.