An Ottawa judge has delayed the sentencing of an 18-year-old woman who pleaded guilty to helping run a teen prostitution ring, saying the sentencing recommendation was too lenient.

The young woman was one of three teen girls charged with human trafficking, assault, and robbery in June 2012.

She was 16 years old at the time.

The teen's lawyer and Crown prosecutors made a joint sentencing recommendation in November, agreeing that she should be sentenced to one year of time already served and two years of probation with strict release conditions.

But on Friday, Justice Diane Lahaie said the one year sentence wasn't enough.

Psychological assessment ordered

She said the 18-year-old should receive a sentence in the range of two to three years given the gravity of the charges and the impact on the victims.

Lahaie also ordered the teen to undergo a psychological assessment, which will take eight to 12 weeks to complete. The judge also wants defence and Crown lawyers to justify why they made the sentencing recommendations they did.

All sides will meet next week to set a date for the sentencing hearing.

Another girl who was 15 at the time of her arrest is expected to be sentenced on Monday. She has also pleaded guilty.

The alleged ringleader, who was also 15 when she was arrested, has pleaded not guilty. A verdict in her trial on 33 charges, including trafficking and sexual assault, is expected on Jan 29.