An ex-midwife on trial over the deaths of two babies during homebirths failed to warn mothers of risks and acted calmly as the children died, a court has heard.

Lisa Jane Barrett, 52, has pleaded not guilty to two counts of manslaughter over the deaths of Tully Kavanagh in 2011 and another baby in 2012, who cannot be named for legal reasons.

Prosecutors say the former midwife, from Petwood, near Adelaide, discouraged Tully’s mother, Sarah Kerr, from giving birth in a hospital, despite the fact she was pregnant with twins.

Speaking before the SA Supreme Court last week, prosecutor Sandi McDonald SC said Ms Barrett downplayed the significant risks associated with a twin homebirth and manipulated a fear of hospitals Ms Kerr had developed after the traumatic birth of a previous child.