From Pathfinder Lost Omens Ancestry Guide, which isn't enabled.

Maiden's Mending

FEAT 1

Activity reaction

Frequency once per minute

Trigger You cast a non-cantrip occult spell or an innate spell from a changeling ancestry feat.

You can tap into some of the magic that flows through your blood to give you new life. You gain a number of temporary Hit Points equal to half your level (minimum 1) that last until the end of your next turn.

Pathfinder Lost Omens Ancestry GuideOGL