Yes, I think the idea was that it was a kind of 'blank' waiting for a personality and memory to be added at a later point (but same difference.)I got the impression it was cloned physically and then had the memories "downloaded". She seemed to be wearing a tiara-scanner for a while...
The umbilical cord to the same place in the neck as the Probic Vent was a suggestion that it was how the Sontarans grow their own kind. The 'water bath' thing was very similar to that in a recent 'Terminator: Sarah Connor Chronicles' episode where a Terminator grew a new skin - though it that the bath was filled with O Negative blood rather than Fluorescein water dye.