I scanned these strips years ago but must have forgotten to blog about them as I've just found them as I was clearing out old files on my Mac. The strip is Cloris and Claire, The Sporting Pair which appeared in June weekly in the early 1960s. (These examples are from 1962.) The artist was the legendary Roy Wilson, sadly nearing the end of his life (he died in 1965) but his talent was as strong as ever. Click on the images to see them larger, particularly the one above which I've enlarged even more to show in more detail Wilson's flawless brushstrokes.
According to Denis Gifford's Encylopedia of Comic Characters the scripts were reworked plots from Reg Wooton's Sporty strips. Cloris and Claire was later reprinted in Sally in 1969/70 and retitled Sue and Prue, The Clueless Two.