The deal, agreed by Camden Council with the National Union of Teachers, is one of the best in the country.
It means that every teacher in the north London borough giving birth after January 1, 2005, will be entitled to 12 weeks' leave on full pay, two weeks on 90 per cent, and 12 weeks on half pay.
National conditions entitle teachers to the same package but with only four weeks on full pay, then eight weeks on pound;120 a week, following a government change for all working mothers introduced in 2003.
Rachel Johnson was one of the leaders of the campaign for a better deal for Camden mothers - but will not benefit as she had her baby Stella in November, two months too early to qualify.
The head of classics at Camden school for girls decided to take a full six months' maternity leave anyway. But her partner has had to work overtime to make ends meet.
"This is a choice we have made because the first six months is such a crucial time in the life of a baby but it has created a huge financial pressure for us."
"The new deal will help relieve other mothers from an inadequate maternity package," she said.
The NUT hopes the deal, which it announced on International Women's Day on Tuesday, can be used to encourage similar settlements elsewhere.
On the same day it also launched a new pamphlet warning schools that playground insults can legitimise domestic violence.
The NUT said offensive terms such as "pro", "slag", "ho", "whore" and "slut" should not be tolerated in the playground and that children aged 11 or younger should be tackled before their attitudes hardened.
Baroness Scotland, the Home Office minister, backed the union's stance, and said that playground bullies often became domestic abusers in adult life.