Did you commit a sin and wrongdoing by lying to your friend, claiming that you dreamed of her and her lovers hanging and screaming, in order to scare her into repenting from the sins she commits, especially since mere advice was not beneficial with her?

What you did, claiming a vision falsely, is impermissible. It would have sufficed for you to forbid the evil and mention God's warning to the disobedient. Do not tell her about your lie; rather, seek God's forgiveness and continue advising her with wisdom and good admonition. If you fear her influence on you, then abandon her, for a companion draws one along, and an associate is influential.