Hello, I Think My Mother Has Cellulitis. She Is 80

Hello, I think my mother has cellulitis. She is 80 y.o cad, hypertension, pad etc. The leg that the site is on is also same leg the has had a bypass several years ago. Do I need to take her to acute care facility tomorrow, er tonight or pcp on Monday? Site is red, painful, not hot to the touch but swollen.