Venuti undergoing surgery for broken ankle

Vivacious singer Maria Venuti is undergoing surgery amid reports she has shown some improvement after suffering a stroke.

The 75-year-old entertainer will undergo surgery for a broken ankle on Thursday, which she is believed to have suffered when she collapsed in her bathroom during the stroke on Saturday.

News Corp reports the singer may have recovered movement in the left side of her body.

Friend Susie Smither says Ms Venuti is heavily sedated and still unable to communicate.

Ms Venuti's daughter Bianca has asked for prayers as her mother recovers at Sydney's Royal North Shore Hospital.

"Mum is going in under anaesthetic to have surgery on her broken ankle this morning ... and then hopefully her breathing tube can come out soon," she said on Facebook on Thursday.

Just before finding her semi-conscious at her Gladesville home on Saturday, police arrested a 38-year-old man who was allegedly stalking Ms Venuti. He was found carrying flowers and trespassing on her property.

He was detained on Saturday for a mental health assessment but has not been charged.