Why didn't you tell us what else Ellen G. White said on the subject?
As in:
"Children who practice self-indulgence (masturbation) previous to puberty, or the period of merging into manhood or womanhood, must pay the penalty of nature's violated laws at that critical period. Many sink into an early grave, while others have sufficient force of constitution to pass this ordeal. If the practice is continued from the age of fifteen and upward, nature will protest against the abuse she has suffered, and continues to suffer, and will make them pay the penalty for the transgression of her laws, especially from the ages of thirty to forty-five, by numerous pains in the system, and various diseases, such as affection of the liver and lungs, neuralgia, rheumatism, affection of the spine, diseased kidneys, and cancerous humors. Some of nature's fine machinery gives way, leaving a heavier task for the remaining to perform, which disorders nature's fine arrangement, and there is often a sudden breaking down of the constitution; and death is the result." (Solemn Appeal, 1870, p.63)."