Would this be considered causing someone to sin?

Before I for serious with trying to grow my relationship with God I had purchased They Buth die At The End and then the second book The First To Die At The End. And now that I'm growing my faith I plan on getting rid of them and in the beginning I asked my friend if she wanted them because she likes anything that's gay, and she said yeah. But now I'm not so sure if by me giving them to her if that's considered causing her to sin. I'm not entirely sure what causing someone to sin really means so that's why I ask because I want to know what it means before giving them to her