Emergency Residence Order

[Maybebaby2010]

Hi I need a bit of advice, my sister Is currently divorced and has a contact order in place with her ex husband the children currently live with him, one of her sons 12 year old came to visit her as usual covered in bruises on his arms and legs saying that his older brother 13 year old had done it, he also said that his dad slapped him round the face a few days previous this happens quite regularly, she hasn't taken him home but did call social services and the police to report this. The police came and took his statement and reported back to social services, social services came today and have advised that he goes home because she's breaking a contact court order but are happy for him to stay with her, she's currently sorting out the court paperwork to try and get a residence order because he doesn't want to return home but is worried that dad could get a emergency residence order because she's breaking the contact order, can dad do this without her knowing or would she have to attend court to contest this?