The grandmother of a toddler who died from a massive head injury and sexual assault told a court she was concerned when her daughter's new boyfriend began bathing the child alone. Alexandra Walker, 25, and Harrison Simpson, 22, are accused of the murder and sexual assault of two-year-old Isabelle Welsh.

Isabelle collapsed at her home in Thornaby, Teesside, on September 13 last year, having suffered a 'massive head injury,' Teesside Crown Court heard. In the weeks leading up to her death, the toddler sustained 21 separate broken bones and was allegedly sexually assaulted.

Claire Walker, the grandmother, testified that while she believed her daughter idolized Isabelle, she grew concerned about the toddler's appearance in the days before her death. She stated that both she and her daughter had reservations about Simpson bathing Isabelle without another adult present.

"He bathed her when she [Walker] was in the hospital. She told me about it. I said, 'don't let him bath her again. Only a mother should do that,'" Mrs. Walker told the court when asked about her daughter seeking advice regarding Simpson bathing Isabelle. The grandmother said she had never met Simpson, and her daughter had explained he had anxiety and did not want to meet her.

Approximately 48 hours before Isabelle's collapse, her grandmother visited and found the child unwell, describing her as "white, had tummy ache, her knee was hurting" and wanting to be cuddled. She also noted a bump on Isabelle's head and, upon changing her nappy, discovered bruises on her back and marks resembling fingerprints near her hip. When questioned by her mother, Walker attributed Isabelle's condition to accidentally banging her head and a virus contracted during a hospital stay for a fractured leg.

Jurors were previously informed that Walker and Simpson used alcohol and drugs excessively. Phone records presented in court indicated that Walker had searched Google to ascertain if Simpson was on the sex offenders' register. Messages between Walker and her mother suggested Simpson had become upset due to a comment about him being a "paedophile."

Walker and Simpson deny murder, causing or allowing the death of a child, assault by penetration of a child under 13, and child cruelty. The trial is expected to last six weeks.