Sleepy Mama With Baby Plaster Casting

Beautiful figure of a sleepy mama with baby on her lap. Feels like a plaster casting, but I can't be sure. Hand painted by original artist. Bottom has the lettering Della Mae. There is a stamped makers mark, but I can't make it out. It's about 20 years old. The wooden chair came with it but never seemed to fit quite right. It sits fine on a shelf, though!