I masturbated and ejaculated on tissue paper in a closed room and wrap the tissue paper properly while wrapping a very small amount of sperm comes on my fingers and then for throwing that tissue paper I open the room door with same hand contain very small amount of sperm on it then after 5 min my sister comes in room and for opening the door she touch on same area where is very small amount of sperm is present. Can she became pregnant by this act? Please help? After touching that area she go toilet after 10 min.