Jemma Appleyard was driving a Skoda Fabia when the incident happened at Retford Oaks Academy, on Babworth Road, at 3pm on May 11, said prosecutor Becky Allsop.
Staff looked after her until police arrived and a test revealed she had 94 mcgs of alcohol in 100 mls of breath, when the legal limit is 35 mcgs.
Appleyard told officers that her mother had died that week, and she was waiting for a call from the undertaker at the time.
She claimed she didn't see the plastic barrier due to a combination of being upset and being intoxicated.
"She bought five or six miniature bottles of wine and drank them while driving around Retford," said Ms Allsop.
The court heard she has a previous conviction for drink driving from April 22, 2018, when she was banned for 15 months.
Nigel Misson, mitigating, said the defendant now recognises that alcohol is an issue and is seeking help.
“She is probably in the middle of a mental health breakdown," he said.
A positive report from probation would provide assistance to “someone who very much needs it,” he added.
Appleyard, 32, of East Field Park, Tuxford, pleaded guilty to driving with excess alcohol when she appeared at Mansfield Magistrates Court, on Thursday.
She received a nine-month community order with 15 rehabilitation days. She was banned for three years, but magistrates offered her a rehabilitation course which will reduce the disqualification by 274 days if completed before July 2023.