When Blaine knocks the daughter out and zips her in a body bag and throws her in the water it would only be a minute and half before she would drown. So if you believe she's a Houdini and escaped the zipped bag from within in the deep water while being knocked out, the next scene when shes on the shore out of the bag they show her waking from unconsciousness. So if she were unconscious how did she get out of the bag? If she fought her way out of the bag she'd certainly be awake when she swam to shore. Or if she floated to shore unconscious she'd still be in body bag drowned. The director picked too final of a way for Blaine to attempt murder because he would have succeeded. No way she came back from being zipped in that body bag knocked out and thrown in the water.