Thank goodness she didn't waste more than $20. She can't restore the phone. She does not know the Apple ID and Apple ID Password used originally on this used phone, so without that she can't use it. Apple won't help. We can't help. The only person who could restore the phone would be the person who owned and set up the phone. If the people she bought it from originally used the phone, they can restore the phone. But it wouldn't be worth the bother either. iPhone 5 is a VERY VERY OLD iPhone. It's not capable of running the newer generations of iOS, so most apps won't run on this phone, such as no YouTube or Facebook. So she would very likely be very disappointed in this phone, even if she could use it.
Honestly, the phone is ready for the recycle bin.