I'm pretty sure that Caprica Six, even post-pregnancy, would do it again if the need arose. Like the rest of the Sixes, and even Head Six, she appears to be something of a solipsist when it comes to human beings who aren't Baltar. At the very least she has an insouciant approach to life and death.
Head Six was never in his head, Kara Thrace was basically the same thing as Head Six after she got killed and came back, the only difference was that everybody could see her. Also Head Six was not really a Cylon, she thought she was for a time, she was different from Caprica Six.