Herbie "adopted by the whole town" Lemon not being as compelled to find out about his parents as Violet because he already has all kinds of parental support that he needs.
Like, he lives at the hotel, where there's Amber (chill sister) and occasionally Lady Kraken (weirdly supportive grandma) (ignore Mollusc)
Dr Thalassi said they used to have lessons in mechanics and stuff. Wendy seems to know every food favourite of his. Jenny sees him so often she's genuinely surprised he never had a second book dispensed. Seagol takes his trinkets for money. Even the fishermen didn't really wanna kill him. One of them said he was even there when they found him.
And yes, every single one isn't exactly a 'parent' on their own, but together, they provide pretty much the same support system.
Violet on the other hand grew up with her aunt, whom, as far as we know was neglectful but rich. She didn't remember her parents either, but she wanted so bad to fill the gap they left. She spent a long while looking for clues towards them and actively put herself in danger for it. She's much calmer in book 2 just because she knows more than they're out there and not dead. That there's a chance she'll find them or they'll find her.
