Ronia Brahe is the daughter of Tycho Brahe and Brenna and the younger sister of Elliot Brahe. She has not played a major role in the comics other than a few mentions and a cameo when compared to her brother and Gabe's children.
As a toddler during Tycho and Ronia's first outside playtime together with Gabe and his son Noah, Tycho took her to a water park where Gabe questioned how much pee was in the pool, Tycho then revealed that it had been empty when he first arrived and that is was actually a play structure which the children had naturally filled up with their pee, including his daughter's pee. Gabe grew weary of this and then Tycho horrifyingly revealed that by six o' clock they allow diving, implying that pee is the source of the park's water.
At two years of age, she took her mother's lipsticks "or some shit" and went crazy up and down the hall with them, stressing Tycho heavily.