Hello, I'm a sort of retired mechanic. I like to work in my in my community.
I don't have a lot of experience in dealing with Santa fe, so I'll do my best to describe.
This lady told me that one of her kids left a dome light on and her battery died and it wouldn't take a jump. Her dad got a new battery and installed it (it's in correctly). Now before the dead battery she said it started every time just fine. Well with the new battery in it won't start, all the dash lights come on when you turn key and battery has 12 volts, but when I try to start it there is nothing. She also said her key faub doesn't work either.

Any help would be appreciated

 

If you are still waiting for help, you might consider the following.
Hit the unlock button on the FOB three or four times and press panic button once. Lock and unlock the driver's door using the key.

Then see if it starts. Let us know how you make out with this , thank you.

 

Thanks