on the expensive side (for monthly cell fees) but this is definitely do-able. Possibly the only do-able.
And on the other hand, maybe it's not going to be so expensive. My wife and I have always used inexpensive cell plans (often prepaid) due to not using them much. I do have data on my own cell as I will use this when I am out shopping. But I am paying only $14 a month for a "2 GB" plan, of which I'm not certain how much or little that is for web usage. Higher usage plans are available.
We use Tello (www.tello.com) which uses the Sprint network.
If I recall correctly, you'll need the SIM card for the iPad, but Apple itself may provide a "universal" SIM (I think it's software, not a SIM card). Anyway, this approach is certainly do-able.
(see here for SIM info for iPads https://www.apple.com/ipad/cellular/ scroll down to "How cellular data works with your iPad.")
@ManicProgressive wrote:
If you don't mind spending the money, the ipad with a cellular connection can do all of that. You could have it shipped to her house. They aren't hard to set up. Or you could have it shipped to your house first, set it up for her, and then drop it off (no contact) if you are close, or ship it to her yourself.
She can load different communiation apps like Skype or Facetime. I don't know anything about What's App, but it sounds the same.
https://www.apple.com/ipad/cellular/