Utley? Girls Christmas Postcard - Dating

[Gmac101]

Hello Everybody,  I'd like some help with this photo of two girls.  They are possibly part of my family who lived in the villages between Barnsley and Rotherham in South Yorkshire.  Most of the family were skilled to semi skilled working class, Coal Miners, Engine Tenders, Foundry Workers and the like.  The aircraft on the back of the postcard looks like a Bleriot XI (though the rear empannage  looks different to photographs of the real plane) which flew the English channel in 1909.
Are the dresses of that period?  Were the dresses likely to have been for special occasions?
Thanks in advance

[John915]

Good evening,

Looks very similar to photo's of my maternal grandmother and her sister. So I would say 1910 to 1920 but could be a few years earlier.

My grans picture is easier to date because they are wearing their WW1 sweetheart brooches.

John915

[jim1]

1908-12. Skirt lengths suggests 15-17 yo with the girl on the right being the older of the two as her hairstyle is more mature.
Dress/hair styles were typical for around 1910.
These outfits look like Sunday best.

[Gmac101]

Thanks Jim1 - That ties in well with the aircraft on the back.

John915 - perhaps they didn't have any Sweethearts?  But I think's it the early part of the decade as Jim1 suggests as that ties in with the Bleriot on the
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