I can't solve the mystery just yet but her date of birth, 24 May 1907, is possibly wrong

If she was 4 on the 1 June 1912 when they sailed, her birthday is somewhere between 2nd June 1907 and 1 June 1908.
On 1st June 1912 she would already be 5 years old if her bday was 24 May 1907.
Also looking at the passenger list, they are going to live with Alice's relative, her brother George, David's brother-in-law but I can't work out his surname.