Wren, 25, was last seen March 31 near Vermont Avenue and Wilshire Boulevard in the Miracle Mile area.
Police did not release any details about how Wren was located, but they said she has been reunited with her family.
A celebrity gossip site described her as Sizemore's girlfriend. The actor's manager, Charles Lago, denies that Wren was Sizemore's girlfriend or assistant. Lago tells People the two knew each other because they lived in the same high-rise apartment building.
The actor was questioned in her disappearance.
Wren's father said she has battled drug problems in the past.