A mother and her boyfriend have been convicted of murdering her two-year-old daughter following a prolonged period of abuse, Teesside Crown Court heard. Alexandra Walker, 26, and Harrison Simpson, 22, were found guilty of murder and child cruelty in connection with the death of Isabelle Welsh, who collapsed at their home in Thornaby, Teesside, in September 2025. Simpson was also convicted of sexually assaulting the toddler.

Prosecutors described a sustained campaign of violence against Isabelle in the weeks leading up to her death. The child suffered 21 broken bones, numerous bruises across her body, internal injuries, and signs of violent shaking resulting in a catastrophic head injury. Medical evidence indicated that Isabelle’s skull was fractured and her brain damaged, consistent with her head impacting a hard surface such as a wall or floor.

Despite the severity of her injuries, Walker delayed contacting emergency services after Isabelle began bleeding. She reportedly searched online for explanations for her daughter’s bleeding and only called her stepfather for help about an hour later. It was on his instruction that 999 was finally dialed. Paramedics arrived within a minute but were unable to save the child, who died the following day in hospital.

The court heard that Isabelle had been brought to medical attention on multiple occasions before her death, including an incident 11 days earlier when she was treated for a broken leg. Staff at North Tees Hospital had expressed safeguarding concerns and were reluctant to discharge the child to her mother, who had shown aggression towards medical staff during their inquiries. Walker told doctors that the break occurred when Isabelle’s leg got caught in her cot, and she had previously waited two weeks before seeking treatment despite the toddler’s difficulties walking.

Family footage and CCTV installed in the home showed Isabelle to be healthy and happy prior to Simpson’s involvement, but concerns were raised about his behavior after he entered Walker’s life. Walker had met Simpson through a dating site just months before the murder and reportedly suspected he might be a paedophile, even checking if he appeared on the Sex Offenders Register. Nevertheless, Simpson was left alone with Isabelle on several occasions, including bathing her without Walker’s permission.

The trial revealed a turbulent relationship between Walker and Simpson, both of whom consumed alcohol and cannabis and at times sold the drug. During the proceedings, Walker blamed Simpson for the abuse and injuries, while Simpson declined to give evidence. His legal representative argued that Walker was responsible for the toddler’s death.

Outside court, Isabelle’s father, Josh Welsh, expressed relief at the verdict and called for whole-life prison sentences for the pair. He described the loss of his daughter as shattering to his family and emphasized the importance of justice being served.

Sentencing for Walker and Simpson is scheduled to take place imminently.