She is playing on the iPad.

I know why she is confused....it's because of Apple. They never refer to it as "the" Ipad/Apple Watch/Iphone.....it's always just Ipad/Iphone/etc. It's like they are talking about a person. Unless you work for Apple, you should use an article (the, an) before it.

"on the IPAD", the countable nouns should use "a/an/the" before them or "s" after them at the most of time.