Marvel, that is a head scratcher!
I assume you've powered off the printer and her iPad — that is, completely shut down both of them. Then, restarted her iPad first, followed by the printer. (Or, maybe the opposite order could work.). It could take doing it twice.*
We have the exact same model of printer — it's a marvel. (No pun intended! 😎) We've been running for TWO years on the original cartridges. Prints incredibly quickly (jobs are done before I can even walk down an half flight of stairs to it). Its black printing is better than our laser printer. It replaced a Brother inkjet that ate cartridges like Pac-Man.
Both of our iPad Airs print to it without issue.
As to settings, I just checked and, as expected, do not find any printer drivers or printer choices in the Settings app, and definitely not under Settings, WiFi.
What you're experiencing is baffling. Is Epson support any help? Or, Apple's?
I tried the following, but it was a dead end. Still, it might give you some ideas of things to try or to check!
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If I start a print job on the iPad, e.g., this web page, I get the Print dialog box, showing me the comment thread's pages on the left, and a dialog pane titled Options on the right where I can select printers. I just tried this and after selecting the Epson, there's an Info button. Click on that to see supply info — but it also has an option to “Show Printer Web Page”. Wonder if that has any extra info — perhaps settings to tweak or that you could use to see if your iPads look the same.
Alas, when I tried it again, that choice disappeared! Weird!
Tried it with an email (your situation) and Show Printer Web Page opened a window in Safari. Unfortunately, Safari displays a HUGE error banner saying “This Connection is Not Private” with warnings that the website might be impersonating Epson local web page and recommends closing the page and not clicking through. So, I didn’t pursue it.
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*I had a weird thing with my iPad the other day where the WiFi setting was blank! No name and no option to turn it on or off! Never seen that before. It required TWO full shut downs and restarts before it reappeared. That’d why I suggested doing the restarts more than once.