Yep, she had little to no care about anything when Minerva was around. The serval worked really hard to keep Hazel's life carefree and painless. Hazel was young enough she didn't know she was being sheltered. She would have dreams every once in a while that haunted her but everyone has nightmares so she didn't think twice about it
But when Minerva was taken, and everyone was telling her the Serval was dead, it started to bring back the pain she felt when her own mother died.
That was when she started to be more concerned about hearing again, as she felt like if she could hear again, she might hear something that helped her rediscover her past
The missing key is her name. Once she hears her name again, it will all come back and when it does, all hell is gonna break lose XD