Spotting new Ali Parker releases used to be a game of checking bookstore shelves, but these days I'm all about following her directly on Amazon. If you set up an author follow for her profile there, you'll get notified the moment a new title drops, which is usually where her ebooks and paperbacks appear first. Her own website is surprisingly static and doesn't get updated as frequently as her publishing pace, so I wouldn't rely on it.
A lot of her stories also pop up in Kindle Unlimited, so if you're a subscriber, you can often find her latest right in the KU catalog. I've noticed some of her newer co-written series with other authors in that 'billionaire romance' sphere can be a bit trickier to track, but searching her name on Amazon sorted by publication date never fails me. I just finished 'The Rival' last week, which I found exactly that way.