Time travel really happens everywhere. Even if you are framed and hit on the head, your soul can travel through time.
Others can travel to the eras they learned about in history books, but she can only travel to another world. Others can also time travel into the body of the rich lady, and in bad circumstances, she can be the daughter of a good family. Although she time travels into the body of the rich lady, she is a rich lady who was sold into a brothel. Others who traveled through time could marry into the royal family or a prince's palace right away, but she could only work hard to earn a living in a brothel, and see if she could redress her enemies and get rid of her status as a government prostitute...