Rafe was NOT raised in the orphanage. He has told the story of his family living in the neighborhood, of how he was on the streets in the wrong crowd (gangs or something) and how the good Sister (Agnes?) took him under her wing and got him on the straight and narrow. Sami once asked him if he had other family and he only said he did not want to talk about that now.
When Arianna first appeared, she definitely said she & Rafe had not seen each other for a long, long time.
And it was Nicole who first appeared in Salem, followed soon by Taylor & Brandon. I remember Taylor was using a different last name and Nicole did not want anyone to know she was her sister. Nicole & Taylor had the same parents, Brandon was the result of an affair. Nicole’s father was very abusive, which is how Abe came to be involved in the family’s lives.