Laura and Alfred were not married. Laura was married to Horace Cadd when she had both Ouida and Othma to Alfred Pettitt, there was a 'legitimate' son but both Ouida and Othma were illegitimate. Othma was brought up by a foster mother, Ada Horley, Ouida spent time in and out of foster care with Ada. No info has ever been found on Alfred Pettitt apart from he is detailed as an Architect on their birth certificates. Laura moved around a lot, she was 'missed' on the 1901 census due to the moves. Othma went to war in 1914, when he returned in 1918 he tried to find both his mother and sister, he never did.
Ouida married 'Carl Sedalia' but left in 1916, she left a baby daughter behind and never tried to make contact. Ouida was only 22 when she left, I find it hard to believe that she didn't have another child. Leonard Wilmin (Carl Sedalia), her husband, was a womaniser. When he died in 1954 he was'married' (no marriage record) to Naomi Wilmin in Bournemouth but living with Eva Wilmin (name changed by deed poll aparently) in Marylebone, London.
Margaret Sedalia (Wilmin) was Leonard and Ouida's only child, she died 12 years ago, my partner (Margaret's only child) is 50 on 25th June 2005 (next week). I started researching his grandfather as part of his birthday celebrations over 6 months ago. So far I have mysteries but no answers!
I've searched 1837 online by quarter from 1915 through to 1970 for Wilmin, Sedalia, Pettitt, Mitchell, Cadd, unknown deaths etc but still nothing.
We have no idea what happened to Ouida.