A Melbourne childcare worker who stole more than $91,000 in welfare payments from Centrelink must spend three months behind bars.

Ikraam Mohamud, 31, pleaded guilty to taking cash from the federal government agency while she was working at multiple childcare centres and failing to notify Centrelink of her income.

The court has ordered Mohamud to pay back $88,000 to Centrelink in instalments of $15 a fortnight, meaning it will take the fraudster almost 226 years to return the money.

The single mother was sentenced to serve two years in prison but will only spend three months behind bars before being released on a court order to be of good behaviour.