I took that opportunity (since she reached out to me unprompted) to ask if she wanted to get dinner. She said "maybe another day."
Should I do anything when she contacts me out of nowhere?
You took the opportunity to pursue... DO NOT pursue. Did she ask you a question or a statement? A response is not even necessary for statements.
When I went no contact, I did not respond to temp check text like "how are you?". Unless it was business related, like dealing with finances or rental property, I ignored everything else personal.
Did you watch any of the YouTube series that I recommended?