A Waukesha woman injured her 4-month-old nephew so bad that it could cause long-term motor delay, blindness and mental retardation, a criminal complaint alleges.

Toni M. Mackay, 36, is charged with physical abuse of a child-recklessly causing great bodily harm. If convicted, she faces up to 10 years in prison.

According to the criminal complaint:

The 4-month-old boy was taken to Children’s Hospital of Wisconsin after Mackay sent a text message Feb. 6 to his mother worried because he was “coughing, rigged and was clenched up.” A social worker at the hospital reported the incident to the Waukesha Police Department because the boy had a brain bleed.

The baby’s parents told detectives their son was vomiting in late January after being in Mackay’s care, so they took him to an urgent care clinic but his tests came back normal. However, the boy was vomiting three times in the hospital on Feb. 6.

Police interviewed Mackay, who told them the boy was crying while she was changing his diaper, so she slammed him down on the couch. The boy’s head hit the wooden area on the couch, which caused him to cry more, she told police. She didn’t tell his parents about the incident.

On Feb. 6, she told police, the boy was crying again and wouldn’t take his bottle. She told police she shook the boy and again slammed the baby on the couch, hitting his head on the exposed wooden frame.

About an hour after the incident, she told police, the boy appeared to go into a seizure. While she knew she should have called 911, she instead contacted the boy’s parents.

A doctor from Children’s Hospital told a detective that the baby had a subdural hemorrhage that was causing pressure on his brain. The doctor indicated the baby faces possible long-term motor delay, blindness and mental retardation, although some cases may be milder. School-age children could have learning disabilities or behavioral problems, the doctor told police.