I've lost it for now, but there is an article on the British Library archive describing Diane as Gary's assistant, from '65 or thereabouts. Clearly the reason she keeps popping up outside the Beat Girls.
And we have three DC groups now, the Katy-Dids/Beat Girls, the Lucky Stars, and Desdemonas.
Diane mentions "Here come the pops" on her bio on the site now up for sale. Strangely she says she also appeared in a BBC production of "What Katy Did" (wihich was in 1962), maybe that was the genesis of the group name.
Rather more strangely, the bio says she appeared in the Jo Cook dancers, I think there's more to this attribution than a mistake in a photo archive.
This is an article from Tatler dated 30-04-66, the article itself is really just a general critique of girls fashions, so i wont post the rest. A slightly unflattering picture perhaps, but it shows the other side to the business of dancing in clubs during the week and not all TV glamour. I think it is Flick, Lyn and Babs shown in the photo, so perhaps they did these type of gigs on a rota basis.