If she was interferring in the arrest of the suspects by the Police , then these things happen.are you talking about the mother with a black eye?
It's unfortunate that she got a black eye but she should accept some liability for her injury.
The Policewoman was battered in an unprovoked attack.
All the suspects had to do was stay calm and co operate with the Police, if they believed that they were being unfairly treated , then they could lodge a complaint later and seek redress or maybe compensation.