Their visit with Him was possible because they were residents not of Heaven but of Paradise. Once Jesus was resurrected they were resurrected also and went to be with God in Heaven. This spirit was referred to as a spirit of divination. Paul finally got annoyed at her public divination of who he and Silas were and cast out the spirit that possessed her. A familiar spirit is a devil.
Devils take on guises.
Spiritualists and New Age people are naive - they think the spirit world is safe to wander around and consult anyone. No, they use any discernment they have. Enter the realm of the Kingdom of God by accepting Jesus as your personal saviour and then receive the Holy Spirit as your personal guide and counsellor. By the Holy Spirit and by the anointing that comes from the Holy Spirit you can receive knowledge of all things that you will ever need to know. No one know the things of God except the Spirit of God.