The hooker, who was part of the team which beat Canada on Sunday, is head of PE at the Hillingdon school.
She told getwestlondon.co.uk that she is looking forward to being back at school repaying its support.
Mrs Croker said: “Being a World Cup winner hasn’t really sunk in yet, it’s a bit overwhelming. But when I go back to school next month it will be an end of the celebrations and a return back to normality.”
All members of the England squad work full-time and need understanding employers. She said: “I love my job. The people there are great and my department is fantastic and everyone at the school has been very supportive.
“It will be great to get back to work and repay that support.”
The weekend’s victory was all the more memorable as England had lost the three previous finals to New Zealand.
Mrs Croker played in the 2010 loss and said: “Those defeats make this all the sweeter. A lot of this squad were there in 2010 and we were determined to put that disappointment behind us and go one step further.”
The 31-year-old plays her club rugby for Richmond and won her first England cap in 2007, winning her 50th earlier this year.
She is also used to doing things the hard way. When seven months pregnant with daughter Lucy, now two, she was diagnosed with pre-eclampsia and underwent an emergency caesarean section at Hillingdon Hospital.
Within four months she was playing for her club, and after five months representing her country in the European championships.
Watching her throughout the tournament in France was Mrs Croker’s family, including Lucy, who joined her in the celebrations on the pitch after the final whistle.
She said: “I’m the only mum in the squad and it made it even more special for my little one to watch me.
“It was a bit overwhelming for her, but she was happy to have her picture taken with the trophy and medal.”
Since returning home, Mrs Croker and her team-mates has been at the eye of a publicity storm. They were honoured at a special function at England Rugby Union HQ in Twickenham and appeared on The One Show alongside Harry Potter star Daniel Radcliffe yesterday (Monday).
But she says being a World Cup winner will not change her, and she doesn’t think it will change how pupils at the Clifton Gardens school view her either.
She said: “The kids are really supportive and love the fact I play for England, but I’m not sure they will change their opinion of me now.
"I am still the teacher that shouts at them when they’re naughty!”