What does in a local boutique mean, @ChimneySweepLiverpool? As you’ve linked the website I’m guessing you’re not limited to an actual physical shop? Have you looked at the rest of the site? While I always enjoy the Sister Jane look, I don’t think this is the best thing they currently have.
And as the owner of a Big Puffy Pale Blue Jacket (from a very different brand) I have to say it’s a bit of a nuisance. Mine is very warm but doesn’t really work with most of my Winter clothes. And is far too heavy for Spring. The Sister Jane jacket presumably won’t be too warm - as 100% polyester. (Might possibly be a bit sweaty, though.) But will it work with the rest of your wardrobe?
My main reservation would be that it does look quite cheap. Combination of fabric and construction. If it’s the colour you love, they have other things in pale blue, with ruffles. Have a look at the shirts / blouses, some of which contain a smidgen of a natural fibre and might perform the same function for much less money.
But if you really want a jacket, given that it’s more than you’d usually spend I’d suggest looking for something of better quality, or holding out until this is at a sale price.