Sandakphu is safe for everybody. If you are aware, nobody can do anything to you. If you try to adjust easily to anyone then it could be a problem for you. Just one tip - Do not stay in trekkers huts and stay in private lodge if you want attached clean and hygienic toilets. https://www.woovly.com/stories/her-solo-sandakphu-trek-for-a-bucket-list Good Luck!!