Sadie Jenkins, 28, of Newport, attacked them while in a drug-induced trance after prolonged amphetamine abuse.
She was cleared of two counts of attempted murder on the grounds of insanity.
At Cardiff Crown Court on Friday, Miss Jenkins was handed the order, which requires drug testing at least once a week.
Her trial heard Miss Jenkins was psychotic and out of touch with reality when she attacked the children with a 6in (15cm) kitchen knife on 7 May 2014.
After wounding the children, she used the knife on herself and later told doctors: "The voices told me to do it".
In the hours before the attack, she was convinced she been sent a "secret message" via US TV show CSI.
The court heard the children were attacked with a steak knife while Miss Jenkins was "in the grip of a psychosis, induced by your past illegal drug taking".
Mrs Justice Carr described the case as a "tragedy" and said Miss Jenkins would take amphetamines on a daily basis and there was "no excuse" for her drug abuse.
She added: "They [the children] will be physically and emotionally scarred forever.
"Because of your psychosis, you did not know what you were doing was wrong."
The court was told that medical experts said she did not require treatment in hospital and that Miss Jenkins has fully recovered from her psychosis.
"Providing you remain drug-free and mentally stable, you present a low risk of re-offending," said Mrs Justice Carr.
Miss Jenkins has taken several drug tests since her arrest and has tested negative every time.
A woman who slit the throats of two children has been given a two-year supervision order.