Dublin Circuit Criminal Court heard that Ms Carroll doesn't remember being attacked and woke up to the sound of the New Year bells to find herself bleeding and coughing up blood.
She put some Sudocrem and Vaseline on the injury and fell asleep for two days. She was brought to hospital by her neighbour as the injury had become septic.
A medical report described the wound as a 2cm cut and said it didn't require treatment.
Lambe, of Mountainview Park, Rathfarnham, had recently completed an eight-year jail sentence for the 2003 manslaughter of Anthony Jordan (54). During a drunken row she and another woman beat Mr Jordan to death using a hockey stick and a mop handle.
Last month she received a four-year jail sentence for an unprovoked assault in which the victim was left scarred for life after Lambe sliced him with a broken beer bottle.
Marie Torrens, defending Lambe, said the facts in this case painted "a grim picture of New Year's Eve" where three women were all drunk in a flat and that some of them were using drugs. She said the victim refused to stop playing a record by Elvis that was upsetting Lambe.
Lambe told gardai that they began rowing and she stabbed Ms Carroll. The victim later told gardai that Lambe was either holding a knife or a scissors and that she began demanding money from her.
She said the next thing she remembers is waking up in the flat on her own to the sound of bells ringing for the New Year and coughing up blood.
She said she noticed an injury to her belly button and blood all over the flat. She said didn't know how she got the injuries.
Garda Anthony Gilleran said the third woman in the flat is charged with production of a knife.