Both Kresint and her youngest sister Lynberlyn have Healing magic.
Now, being older and having discovered her powers only a short period after Mummo (paternal grandmother/Palace Healer) died, Kresint is the go-to Healer for all the kids, despite only being 11yo by the end of the series. Her Healing manifested before her Hydromancy, but wasn't noticed till long after. It started with self healing, her body just instinctively using magic to heal everything instantly, despite the magical exhaustion of healing hitting her all at once rather than the physical exhaustion of such lasting for a longer period of time. And she didn't even notice getting injured most of the time, and merely thought things like the two days in bed were sleeping off a cold rather than magical drain from ealing something far more serious. Once her powers have grown with age and practice though she can heal others easily. For little things like a skinned knee she'll literally just say "Walk it off!" and the wound will vanish. The greater the wound/illness the more physical interaction needed to heal it, and the more energy it drains out of her - and knowing the specifics of what she needs to fix lessens those needs - but she'll still pass out (on her patient) after healing something major.
Lynberlyn's healing works a little differently though. She’s only a newborn at the start of the series and thus hasn't had any powers manifest yet, but it quickly becomes apparent, and it's public knowledge that she's a Healer long before her Zoolingualism awakens. Years after her power manifests she'll still come running to her big sister crying that she fell off the swing and scraped her hands, and Kresint will heal it simply by wiping her tears away. Even when trying to, she can't manage to heal herself till she's in her mid teens. But even as a toddler, she subconsciously heals those around her. Saphori and Mawilla will bonk heads while playing, and she'll literally kiss it better mimicking the placebo/distraction she's seen the adults and older kids do. Terann has muscle aches from training too hard and a hug from her makes it all go away. Kresint is unconscious but still thrashing in pain from trying to heal something beyond her abilities, but her baby sister climbs into bed with her, and suddenly both are sleeping peacefully.
Kresint's healing first manifests by making her seem invincible no matter what happens to her. Lynberlyn's manifests by reminding her loved ones that they don't have to, but making them feel like they can be invincible.