Evil,
I have copied and pasted below the rule from the OHSAA website. Since it appears the player to which you refer is the only girl from that particular high school on the summer team, the coach is ok. High school coaches, you will find, are professional and do their due diligence to do what is right for their high school and its athletic programs
4.9) Members of the Interscholastic Coaching Staff - Team Sports - In non-interscholastic participation (contests, tryouts, training and practices) in team sports, members of the school's interscholastic coaching staff may coach interscholastic squad members from the school district where employed for a maximum of 10 days from June 1 to July 31. The 10-day limitation applies to the entire coaching staff. Each individual coach is not entitled to 10 different days for coaching.
Note: The Board of Directors may further limit the number of contact days during this period as specified in the specific sports regulations.
EXCEPTION 1: The paid or unpaid interscholastic coach employed by a Board of Education or other governing board may coach interscholastic squad members from the school district where the coach is employed as coach without limitation from June 1 through July 31 if the 50% limitation is observed. The 50% limitation is defined as a maximum of 50% of the members of a team as defined in the playing rules of the sport. The following chart indicates those limitations for OHSAA recognized team sports.
50% Limitation on Sport Number of squad members
Baseball 4
Basketball 2
Field Hockey 5
Football 5
****** 5
Softball 4