Thanks, girls!

Some of the ones you've suggested have gone on a new shortlist, all okay with DP (he's not really being difficult, we just allow each other right of veto with no explanation needed).

Alice (means Noble)
Carys (means Love)
Clare (means Bright)
Kate (means Pure)
Katherine (means Pure)
Kristen (means Christian, which is fine for us)

opinions on what goes best with our other girls? Charlotte was on the list, but our 11 yr old dog is Charlie, so it's a bit too close. Would go back on if we got desperate.

Middle name will be a family name, so we have several options that can suit most. Katherine/Kate is a possible middle name.
I have a Cerys - same meaning alternate spelling. Only about 50% of people say it right and some can't get their head around the hard C even when have heard it several times they see it and say more like se-riss. The Ca version might work better. Is a very popular name in Wales and therfore in England people know it (also Cerys Matthews from Catatonia made it known) but never occurred to us here people wouldn't get it - and if I had I might not have chosen it. I do think it goes well with the other names both favorites of mine.