That was over 31 years ago in 1990.
Today she is 67, and has starred in 54 movies in total, 41 since Home Alone was released.
In Home Alone, I think Catherine O'Hara looks:
Home Alone scores 7.1 out of 10 on The Movie Database.
Catherine O'Hara's first acting role was as 'Malicious' in Witch's Night Out, released in 1978 when she was 24.