Molly O'Riordan said she asked doctors at Southampton General Hospital to admit her daughter, Jessica, and have her seen by a psychiatrist after a suicide attempt on Monday in which she threw herself under a train.
"She didn't leave the hospital with the consent of her family. She didn't leave the hospital with my consent and they wouldn't admit her," Mrs O'Riordan, 46, said.
The following evening, Jessica went to a concert by the pop group Pulp in Bournemouth. After the concert, she went with a friend to a hotel where she jumped to her death from a fourth-floor fire escape.
Mrs O'Riordan, a social worker who specialises in fostering and adoption, said yesterday: "When I arrived at the hospital, I said to the doctor, 'Look at the state of her, she's shivering'. There was nothing physically wrong with her but I said that she should be kept in overnight . . . The duty doctors assessed her as not being suicidal. They were wrong.
"Everybody can be wrong and people make incorrect professional judgements all the time and that's life, but I didn't want her discharged.
"The police officer with me also thought Jessica should have been kept in for the night."
A spokeswoman for the hospital refused to comment in detail because of the forthcoming inquest on the death. But she said: "The fact is that there was discussion and that discussion included the patient, who was uninjured.
"Our doctors made a clinical decision that she should be allowed home with a competent adult, her mother."
Mrs O'Riordan, of Totton, near Southampton, said her daughter had not seemed unhappy on Tuesday, in spite of the previous evening's suicide attempt. "She was sullen and miserable in the morning but was in better spirits later in the day. I asked her several times if she had any intention of doing what she had done before and she said 'No, absolutely not'."
Mrs O'Riordan defended her decision to let her daughter attend the concert. "It was a birthday treat and the tickets had been bought weeks earlier and she was going along with her sister and her friend. I had a long talk with her before she left and I told her 'no drinking, no messing around', and she really wanted to go. It was her favourite band and I didn't want to punish her for her depression."Reuse content