While the EU as a whole is probably quite open to the idea of welcoming Scotland, there are a few very real challenges ahead for Scotland before this happens.
Scotland will need a unanimous council vote before the accession talks even begin.
Spain will want to make sure that Scotland leaves the UK in fully constitutional manner, to avoid domestic issues in catalonia and the basque country.
Then it will need to settle a divorce with the UK and sort out its trade relationship, borders and
create a central bank and somehow come up with a currency.
The there is a genuine concern from the "frugals" not to have another net beneficiary in the club. Scotland will have to somehow prove that they are not going to be another subsidy black hole.
I think it's safe to say that Sturgeon will not get a fast track promise, or a blank check to join. I'm sure they will join at some point after leaving the UK, but it's going to be quite a shitshow until this happens, if Brexit and the irish border have taught us anything.
Edit: an article on politico today on exactly this.
https://www.politico.eu/article/hast...uropean-union/