If I'm being real, the absolute number one way is to just sign up for her newsletter. She's got a proper mailing list and she's good about using it. I know everyone says 'follow on social media,' but those algorithms are so unreliable. One week you see every post, the next you get nothing. Her newsletter hits my inbox directly, and she often includes little teasers or cover reveals there first.
Plus, she's active on Instagram, but it's more personal stuff mixed in. I check her page every so often, but for the actual 'a new book is coming' alert, the email list hasn't failed me yet. BookBub alerts for her name are a decent backup too, especially for sales on older titles.
Honestly, just go to her website and plug your email in. It's the simplest method and you won't miss a thing.