Good evening,
The Norfolks were given the right to wear the figure of Britannia, on her own, by Queen Anne in 1707. Quote from General Bainbridge 1848 when presenting new colours;
"This distinguished badge was given to you for your gallantry at the battle of ALMANZA, during the war of succession in Spain, by Queen Anne. On the occasion of that battle it is recorded that you lost 24 officers and had 300 killed or wounded out of 467. In retiring from the field the regiment covered the retreat of General Lord Galway, a most arduous, hazardous and difficult service. The regiment thus upheld the honour of Great britain, and was honoured for it by Queen Anne by allowing them to wear the figure of Britannia on their breastplates".
Like many regt's the badge has probably undergone several transformations over the years but it is wrong to say she was first used on her own after 1937. Also as I previously mentioned, cap badges varied between other ranks and officers in many regt's, even today.
John915