@candyquilt-- Yes, women can use electric eyebrow trimmers. But I suggest getting one that's specifically made for use by women. These do exist, I saw one at the store the other day. I think electric trimmers made for women often have a smaller and slightly differently shaped tip to make it easier to use. I suppose you could use one that has been made for men, but you may need practice to learn to use it properly.
Eyebrow razors are often used to shape and thin eyebrows by shaving off excess hair. For example, you can use a stencil to determine the extra hairs and shave them off with a brow razor. But they're not good for trimming. In fact, I think you may hurt yourself if you try. So stick to electric trimmers or a good old makeup scissors.