I recommend:

The Joy of First Year Piano by Denes Agay

An excellent Beginners book for all ages. Easy to follow. Well illustrated with balanced progressive learning. What is so beneficial is the optional duet part for teachers to accompany their students with. It can be frustrating as a beginner  playing pieces which are not so easy on the ear. The optional duets make playing fun and those first few months of playing basic melodies sound like masterpieces when played along with the teacher.