A woman who maintained a sexual relationship with a 13-year-old boy has been jailed for at least five years.

Deborah Goulopoulos, 52, pleaded guilty in the Victorian County Court to maintaining the relationship with the boy for two-and-a-half years between 2002 and 2005.

The court heard she plied him with drugs and alcohol and showered him with $40,000 worth of gifts.

The court heard the boy later developed a drug addiction.

The judge said given the age gap, she considered the woman's behaviour as predatory and said she had behaved like a self-centred teenage girl looking for acceptance.

However, the judge decided that Goulopoulos's immaturity reduced her moral culpability.

She was sentenced to seven years in jail with a five-year non-parole period.