I am not privy to the thoughts of Nicola Sturgeon and her team but do see that there is enormous pressure from the wider Independence Movement to call a 2nd referendum NOW. However, there is another option, which is to declare, citing the Claim of Right, that the Treaty of Union has been breached, many times, and therefore the Treaty is null and void. The Claim of Right, which gives the people of Scotland the right to self determination, was verified recently at Westminster and has also been recognised by the EU. If this route were to be taken then the SNP MPs currently sitting in Westminster, would return to Scotland and sit instead in the Scottish Parliament.
While the SNP has been trying very hard, in good faith, to ensure a 'soft' Brexit for the whole of the UK, this now seems unachievable. Unlike Mrs May, Nicola has plan A and plan B with all the ducks (legal advice etc.) in a row for either option. She has always said that she would make her move when the outcome of Brexit is clear. There has yet to be any such clarity but as the deadline approaches, we can expect an announcement/statement in days or weeks.
If I were a gambler I would put my money on Burns' Birthday ............Coming shortly.