Michael Monckton is charged with second-degree murder in the death of the two-year-old in Januray 2010.
Monckton has pleaded not guilty to the charges against him.
On Friday, Worral was moved to tears when the court was shown pictures of the toddler happy and carefree, before Monkton moved in.
It was a stark contrast to photos taken days before Keagan's death. By then Monkton was taking care of Keagan because Worral was working nights and he had been laid-off from his job.
Worral described one of the photos she was shown: "I see a bruise on the bridge of his nose. In his left eye there's a spider vein. It looks like on his right cheek bone there appears to be a bruise."
She testified Keagan got the bruises when he was alone with Monkton in the kitchen. He told her Keagan slipped and fell from a chair.
Worral recalls hearing the child cry. When she rushed into the kitchen she found him on the ground with a bloody nose and covered in vomit.
Worral will be back on the stand Monday and is expected to recount her version of the day Keagan died.