Should I mention I'm reapplying?

In December of last year, I applied to work at a highly accredited school (only saying this so you know it's not just a random position where a million people are applying a day and they couldn't care less about me), and received a message a few months later for an interview. But, at the time, something was happening personally that hindered me from being able to work, so I politely emailed them to let them know something personal was happening and I needed to pull my application.

The hiring agent said thank you for letting me know, if something changes and you want to interview, please reach out.

Well, now that I've worked through the personal thing, I'm reapplying. Should I mention in my cover letter that I'm reapplying? Should I email her in the email chain? Make a new email chain? Should I not mention it at all and just reapply?

What's the etiquette here?

Thanks in advance!