You should* update her resume, shop around her resume, look at some job postings, and get her to talk to some recruiters.

Update her Linkedin too.

It’s one thing to talk about a theoretical possible new job that might be better. It’s another to present her with: “These companies will hire you at X% higher and their Glassdoor reviews are better than your company”

I was like that (comfy in my old job) and it wasn’t till I was confronted with job postings that were 50% higher pay that I was qualified for and at a better company that I realized I was underpaid and needed to switch jobs.

Edit:

* offer to or encourage her to. Maybe it’s a bad idea to go behind her back and update her LinkedIn and resume though you could still check out job postings and glass door reviews.