Each blow and every kick all but reminded her that Gal would die if she doesn't end this soon. But also the thought that Razhal may hear this and come to check was even a more driving force.
Gal is a true blood serpent and wouldn't immediately die from a pierce through the heart unless left unattended. Her life force lies just below her stomach and it's the same with all other adult true bloods.
The same can't be said for Verona since she's turned. The Masai that initiated the conversion told her there was still a part of her former self in her soul but it has been repressed. So as normal, her own life force remained the same.
The Princess was going around her and she did the same, each waiting on who would move first. But all the while she kept on taunting the redhead, provoking and goading her to break temperament.