it may help to know that her actual date of birth, from her school admission record, is 29 Sep 1891. her middle name was Louisa.
Angelo Michael Caira's WWI service records are on Ancestry - he's called up in 1918, living in Treforest but with parents from Islington and his occupation fits Dolly's husband. No mention of wife or children. His medical records are interesting - he is diagnosed with an illness which if known about in 1917 could have lead to arguments between a husband and wife.
Do you have a tree on Ancestry? There's one with a similar name to yours that suggests divorce on 31 jan 1927 and linking to an outbound record of a Louisa Caria of the right age heading to Halifax, Canada [the image suggests to me however this may be a misreading of the name]
