Who is Galina from Blood Promise and what is their importance?

Galina is Dimitri's former trainer. She was changed into a Strigoi years before him, and Dimitri visits Galina upon becoming a Strigoi. Dimitri receives Galina's permission to change Rose once she is captured, but Galina grows impatient when Rose delays her decision to be changed. Dimitri later kills Galina to keep her from killing Rose.