There are 4 Plaskett/Scott births in Nottingham from 1930 to 1939. The 3 siblings appear in 2 trees on GenesReunited, but Ivy Ellen is recorded as Ivella born 1937 in both.
Perhaps she changed her stage name to Ivella xxxx, and then married under that name.
There is a marriage of an Ivella Blake to Turner in 1963, and then a possible further marriage of Ivella Turner to Rowe in 1977. There is a death of an Ivella Kim Rowe in Hartlepool in 2001, with a birth date of 06/09/1939. Highly speculative, so exact date of birth would help.
Added: Mr Turner probably died in 1976.