Rose Rome is a pre-made elder Sim who lives in Barnacle Bay. She has been described as an elderly gypsy that has been seen rummaging through trash, and some believe she can see into the future of Sims' lives. She wears an outfit that is similar in style to Ginia Kat's, although it's more colorful.
In Wren's biography, it states that she is Wren Rome's great-great-great-niece, but technically they aren't related by family. Most likely, EA did not want to create several ancestors for Rose and stated that for storytelling purposes.