1987 saw a tour of paintings by
Andrew Wyeth, all of the same model.
What was the model's name ?

Helga Testorf - she was his neighbor and nobody knew that he had been painting and drawing her. He painted more than 247 paintings of her - which were not merely a portrait of Helga, but his intent was to do a study of the effects of light. I had the opportunity to see the exhibit at the MFA Boston and it was phenominal!!

Correct (and an awesome answer !)

Thanks Lyds !