Hi there and welcome
On her iPad to be one, Go to Settings > General > Cellular and tap Set Up Personal Hotspot —if it appears—to set up the service with your carrier. After you turn on Personal Hotspot, other devices can connect in the following ways: • W-Fi: On the device, choose your iPad from the list of available Wi-Fi networks.
If it does not appear it means the carrier (your cell provider) is stopping it and it is not possible. It is not a limitation of the iPad but a restriction set by the carrier
If you have continued problems, or would like any additional information or assistance, please do not hesitate to let me know.
And if you can take a second to rate my service by clicking one of the stars at the top of the screen then submit, that would be greatly appreciated.