Kotch (1971)

Joseph Kotcher, a retired traveling salesman, lives with his son Gerald and daughter-in-law Wilma in Los Angeles. He dotes upon his young grandson Duncan irritating high-strung Wilma to the point that she hires Erica, a high school student, as a regular babysitter to replace his efforts. However, Grandpa Kotcher still gets on her nerves, and she convinces Gerald to move him out. To humor his son he agrees to take an apartment at a retirement facility, but after being subjected to some psychological tests he opts instead to take an extended vacation, traveling up the coast by bus. Erica leaves town at the same time, for upon discovering she is pregnant, Wilma fires her and she is sent away to work in San Bernadino by her uptight older brother Peter, who is also her guardian. Grandpa Kotcher returns weeks later to find a Halloween party underway and his room full of Wilma's sewing stuff. A waiting card from Erica explains that due to "serious difficulties" she cannot repay some money he gave her. After an abrupt reunion with Duncan, he immediately slips away to find Erica, finally tracing her to Palm Springs where he decides to stay and rent a small house. No longer able to work as a beautician as her size grows, Erica finally accepts an offer to stay with him by unexpectedly appearing at Christmas time.