Ms Miller, a philanthropist and investment banker, was targeted by Brexit supporters on social media after the High Court verdict was announced.
Many of her detractors made overt reference to her Guyanese heritage, and several said she should leave the UK.
One Twitter user addressed the referendum result: "If Gina Miller really doesn't like what the majority voted for on 23rd June then why doesn't she f*** off back where she came from."
Ms Miller also received a lot of support from Remain supporters.
Ms Miller's lawsuit challenged Theresa May's plan to trigger Article 50 using Royal Prerogative which would have meant it would not require a Parliamentary vote.
Lord Chief Justice Thomas and two other senior judges agreed with Ms Miller and said in a statement: "The court is not concerned with, and does not express any view about the merits of leaving the European Union: that is a political issue."
Following the High Court ruling, the businesswoman said: "It's about our United Kingdom and all our futures. It's not about how anyone voted.
"Every one of us voted for the best country and the best future.
"The judgment, I hope – when it's read by the Government and they contemplate the full judgment – that they will make the wise decision of not appealing but pressing forward and having a proper debate in our sovereign parliament, our mother of parliaments that we are so admired for all over the world."
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