Sarinilli is kind and caring, but can be very harsh at times. She takes her duty very seriously and can be a bit bullheaded at times. Once she sets herself to something, she will see it through. She can be very easy going when she's not absorbed in her tasks. She holds onto a strong moral and value system, and holds loyalty and honor in high regard. She doesn't trust easily, and has a serious dislike for those who behave too familiar or "get up in" her personal space before she's ready to allow them. She's very much a follower of proper procedures, and will tell someone if they're behaving improperly. If you're someone she has deemed worthy of trust or friendship however, she's a much softer person than her walled up exterior would suggest.
Not much is known about Sarinilli's personal life because well, it's personal. She has been known to write letters however in her down time, presumably to her parents or other family, suggesting that she's got a close bond with them. She has shown interest in various people, race and gender don't seem to be a hindrance to who her eyes will follow. She claims not to be in any "romantic entanglements", and currently doesn't seem to be looking for anything serious.
She would follow Queen Ayrenn into the depths of the Daedric Realms if she thought it would help her and the Dominion bring peace to all of Nirn.
Sarinilli is devout to Auri'El, and keenly follows the Path to Alaxon, though she has been known to bend the rules here and there based on her own personal opinion on the world and what perfection means to her.