No. The creativity in Dr. Seuss' stories came from him alone. His wife had no part in the actual writing. He was renowned for his creativity, and his stories were a product of his own thoughts and ideas. There's no evidence to suggest his wife was involved in writing them.
There are numerous drafts in Dr Seuss' own handwriting that show his creative process. Also, his unique writing style with its rhymes and made - up words is a signature of his own creativity.
Yes, she did. Her writing might have been inspired by her life with Dr. Seuss, sharing some of the same whimsical and imaginative elements that his works are famous for. Maybe her stories were read and loved by a smaller audience, but they still added to the overall body of literature associated with the Seuss family.