The court is set to hear oral arguments before ruling if a prospective Bill to hold another vote is within the powers of Holyrood.
The First Minister is hoping to hold a vote next October, if given the green light.
Speaking on the BBC’s Sunday with Laura Kuenssberg in Aberdeen, where the SNP is holding its conference, Ms Sturgeon said: “There’s little point speculating on the outcome of a court hearing, but should that be yes, we have the plans ready to go to legislate.
“Work on refreshing and updating the substantive case for independence is well under way – that will continue over the course of the next days.”
She went on to say she is “confident Scotland will become independent”.
The First Minister added: “If the Supreme Court paves the way for a lawful referendum next year, I think the vast majority of the people of Scotland would take part in that.
“The UK Government might decide to say they don’t want them to take part in that, but I don’t think that is going to prevail.
“If you’re confident in your arguments in politics, if you’re confident in the case that you’re making, then you don’t fear democracy, you actually relish the opportunity to put your case before the people and let the people decide.”
Asked whether she would prefer Keir Starmer or Liz Truss to be the Prime Minister after the next general election, Sturgeon said: “That’s not a difficult question.
“If the question is whether I would prefer a Labour government over a Tory government, I detest the Tories and everything they stand for, so it’s not difficult to answer that question.”
Ms Sturgeon said the UK Government should be “clamouring” for an independence referendum if they believe in their case for the union.
The First Minister said: “I believe very firmly – and I think this is a bit of an iron law of politics – if the other side of this debate really believed people in Scotland didn’t want a referendum and if they really believed that people in Scotland would vote against independence – they’d be the ones clamouring for a referendum.”
When asked if it is possible the UK Government wants to avoid the “disruption” that would stem from a referendum, Ms Sturgeon said: “Disruption? Perish the thought we would have disruption in people’s lives right now.
“The disruption that people are suffering right now are coming from decisions that have been imposed on Scotland against our will.”
The First Minister pointed to Brexit and the UK Government’s mini-budget as decisions imposed on Scotland/