My(29F) boyfriend(27M) is very close to his mentee(14F)

My boyfriend and I are in the dating/getting to know each other phase so I wouldn't consider that we are "going steady" yet but we flirt with each other like we are steady. We have known each other for about 2 months.

He is a youth pastor who mentors a group of youths of mixed genders. A few days ago we were talking about the youths and their activities and he brought up how there is one girl who he is very close to. His exact words were "she is 14 years old but thinks and acts like an 18 year old" and she is "very clingy" and he feels like she is a younger sister. Then he tells me that they talk every day and she tells him everything about her life like who she is dating, how she feels about the guys she's dating and how she sometimes feels depressed and suicidal. He told me they share a lot of common interests like gaming and movies and they would sometimes talk for hours about these topics. He appeared to be extremely happy that they had this close relationship.

Having once been that young girl who needed a mentor to talk to when life got hard, I understand the girl and feel for her. However, alarm bells are ringing in my head over how pleased my boyfriend seems to be about having this close relationship with a young girl. Perhaps it is because there are many horror stories in my country about teachers falling in love with their students, and 40 yo men leaving their wives for 19 yo, but I am wondering whether I am overthinking this since after all he is a youth pastor and it is his duty to take care of the youths.

Am I overthinking in my suspicions of my boyfriend's close relationship with a 14 year old girl?