Complex sentence: Johnno arrived in Hollyoaks with his wife Frankie, and their children Jake, Debbie, and Craig to join their youngest daughter Steph who had been a student at Hollyoaks High School.
Split into simpler sentences: Johnno arrived in Hollyoaks with his wife Frankie, and their children Jake, Debbie, and Craig. Their youngest daughter Steph was already introduced as a student at Hollyoaks High School.