Bill Wingell for The New York Times Marla Olmstead with her painting "Ornaments." She has sold 24 paintings and put $40,000 away in savings. The artist has both her admirers and her critics. -------------------------------------------------------------------------------- BINGHAMTON, N.Y. - The hottest new abstract artist in town has reason to celebrate. This summer, she went from selling her work in a coffee shop to having her own gallery show. After a local newspaper's feature on her, about 2,000 people came for opening night - everyone from serious collectors to the artist's preschool teacher. She earned more money than she could comprehend. The...