Many Adventists will shun away from the term prophetess or prophet and prefer instead that she had the gift of prophecy. EGW herself said that she was not a prophet (she said that she was more than the word prophet signifies).
Here is an excerpt from the EGW Estate Website:
"In brief, she was a woman of remarkable spiritual gifts who lived most of her life during the nineteenth century (1827-1915), yet through her writings she is still making a revolutionary impact on millions of people around the world. During her lifetime she wrote more than 5,000 periodical articles and 40 books; but today, including compilations from her 50,000 pages of manuscript, more than 100 titles are available in English. She is the most translated woman writer in the entire history of literature, and the most translated American author of either gender. Her writings cover a broad range of subjects, including religion, education, social relationships, evangelism, prophecy, publishing, nutrition, and management. Her life-changing masterpiece on successful Christian living, Steps to Christ, has been published in more than 140 languages. Seventh-day Adventists believe that Mrs. White was more than a gifted writer; they believe she was appointed by God as a special messenger to draw the world’s attention to the Holy Scriptures and help prepare people for Christ’s second advent. From the time she was 17 years old until she died 70 years later, God gave her approximately 2,000 visions and dreams. The visions varied in length from less than a minute to nearly four hours. The knowledge and counsel received through these revelations she wrote out to be shared with others. Thus her special writings are accepted by Seventh-day Adventists as inspired, and their exceptional quality is recognized even by casual readers. "