The writer, who has lived in Scotland for most of her life, was a high profile campaigner against independence in the Scottish referendum two years ago.
She even donated £1 million to the anti-independence campaign and was a victim of online abuse.
She tweeted today: “Scotland will seek independence now. Cameron’s legacy will be breaking up two unions. Neither needed to happen.”
She added in a later tweet; “Many no voters will think again now”
Former Labour spin doctor Alastair Campbell also claimed the country is now looking at the break-up of the UK.
He told Sky News: “One of the so-called project fear arguments that we kept trying to get over in this campaign is that there were incredible possible unintended consequences of a vote to leave the European Union.
“One is the break-up of the United Kingdom, I think we are looking at that.
“I think the fact that within Northern Ireland and its relations with the Republic, there’s going to be all sorts of things that will go on there that will be quite worrying.
“Nicola Sturgeon, to my mind, the vote having gone as it’s gone in Scotland, I think she’d be perfectly entitled to press for a second referendum and I think given the public mood about politics and economics in this country then I think it’s possible that there could be one.
“This is not just meltdown in the markets, there is so much going on here.”