Green’s Dictionary of Slang

(UK society) army officers, esp. those who had returned from fighting in the Crimean War (1854–6); by ext. one who is spoiled.

1883		press cutting in J. Ware Passing Eng. of the Victorian Era (1909) 101/2: But it is needless to cite instances to be found by the score in warlike annals, from the ‘Gentlemen of the French guard fire first’ at Fontenoy to the well-fought field at Inkerman, when the ‘curled darlings’ approved themselves metal of the right temper.
1900		Edinburgh Eve. News 28 Nov. 2/3: At the outbreak of the war Society was very bitter against the Boers, but so many of its curled darlings have fallen that a really sober spirit prevails to-day.
1902		Bulletin (Sydney) 18 Oct. 10/2: This pampering is repugnant to people with any manliness or decency in their composition. But I am satisfied that the Australians are feather-bedders, growlers, grumblers, curled darlings, and no-account men. They were cracked up – by themselves – during the campaign, and now they want to travel first-class, and be feasted on chicken and champagne for evermore. Great Scot!