When a stern principal asks a new teacher to look over a specific child the new teacher finds herself in the middle of a family breakdown.

thats a good suggestion

In the logline, the teacher comes off as passive: She's asked to do investigate rather than take the initiative herself, and she "finds herself" rather than does something.

Edgewater's statements based upon his experience suggest a better way to generate dramatic conflict: 1] She takes the initiative to investigate -- doesn't wait for someone to ask her. 2] She chooses to get deeply involved in spite of official policies and procedures.

It appears that the teacher is the lead character, I would change the logline to reflect that.

"When a new teacher is asked to look after a troubled but gifted student..."

Always begin your logine with the lead if you can.

Hope that helped, good luck with this!