First time cockatiel owner..a few questions :)

SO. i am a first time cockatiel owner but i have had three parakeets, they are all gone now sadly. So i got a cockatiel for my birthday. My tiels name is mochi. She is around 6 months old. She is really sweet and has never hissed or bitten me. The only time she was visibly upset was when i first got her into her cage but thats a given. Her body language is very calm. She will take a treat from my hand and she is not scared to eat and drink near me.She is also comfortable sleeping near me too. She has let me pet her head and is comfortable with my hands. Her cage is next to my bed and at night she will sit as close to me as she can. BUT she has not been loud, she has only loudly chirped a few times. She has only been beak grinding. She does it right before bed and after she had a treat. She also makes very quiet chirps that i can only hear when i am very close to her. I am worried because i dont know why she is comfortable with me but is not making loud noises.