If she hasn't sent you the money by now, that's a bad sign. However, worth asking her one more time.

Print out / screenshot the amount owed and ask her to send you payment via check (don't assume funds being available means they really are - wait it out several extra days) or Zelle (safer and convenient). Alternatively, via Venmo or Cash App.

EDIT: She might be able to pay the bill directly herself. Another option, but not sure how practical that is, since she's not on the account.

If she won't pay, then contact EZ Pass and explain you want to pay, but can't afford the amount. They may be able to reduce the penalties and/or offer other payment options.