I have decided this will be the name for dc3. I'm not actually sold on Cassandra as a name, but love the shortened versions. Figure putting the long name on the bc will give her options later on.
My quandary, how do I convince dp it is THE name? He claims he doesn't like it. Obviously, he's a deluded fool but how do I get my way again? 
I have named our other two dcs, so it could be argued its his 'turn'. But I've only done that because he has awful taste! Dss, for example, has 5 middle names. None special or sentimental, just film stars he liked at the time
.