A recovering alcoholic has won a family court fight over the future of her toddler daughter.

The girl, who is now about 16 months old, was placed into foster care at birth.

Sutton Council social services staff had raised concern about her mother's drinking and said the girl should be adopted, but a family court judge has ruled she should go home.

Judge Carol Atkinson said evidence showed the woman was battling her addiction, had been sober for the best part of two years and was committed to Alcoholics Anonymous.

She said the woman, who spent much of her own childhood in care, would need to be strictly monitored by social workers when caring for the girl, but it was not possible to conclude that adoption was the only answer.

"The mother had a difficult childhood, lived largely in care," said Judge Atkinson.

"She is an alcoholic and her addiction to alcohol began when she was a teenager."

The judge said the woman had been sober for more than 20 months, had committed to Alcoholics Anonymous, and had demonstrated "insight" into her condition.

"Having heard evidence from the extended support network and seen that the mother has continued in her sobriety, it is not possible to say that nothing else but adoption will do for this little girl," the judge said.

"The case is still finely balanced but that balance now falls clearly, in my view, in favour of (the girl) being returned home under conditions of strict monitoring."

Judge Atkinson analysed issues at a recent hearing in East London Family Court and outlined detail in a written ruling published online.

She said Sutton Council was the local authority involved, but the child could not be identified in media reports.