Thanks everyone for giving so much help for the first name of DD. Now coming back for middle name help!
We're nearly 100% on Clémence, and our surname is Dufour. There are two grandmothers' names we might like to use - Betty (a French name as well, believe it or not!) and Aimée.
Some reservations about these - if we go for Clémence Aimée Betty I don't like the way the first name runs into the second name and creates a 'sss' sound. However, reversing the middle names creates the initials CBA 
Also, I'm not sure that a run of four two-syllable names sounds very nice.
So, over to you wise Mumsnetters to sort this out! Thank you!