Hi Marie,
Is your iPad wifi only? If it is one that can be used on a cellular network plan then you will get that message. The message will say that you have to connect to wifi to download apps that are larger than 50 mb if you are connected on the cellular network.
Let us know what kind of iPad you have to help you figure this out.
If you only have a wifi only iPad and are using a portable hotspot I don't know why the portable hotspot would have a limitation. Is there nearby wireless hotspot that you can test out your iPad? Some place like a library or fast food restaurant?
If your iPad has both wifi and cellular (3G/4G) you should be able to turn off the cellular data connection when you are using your wifi so the wifi will take precedence and you should not experience the 50gb limitation.
Oh, a way to tell if you have a wifi connection is if you see an icon on the top left hand side that has a dot and two arcs above it when you are connected to a wifi signal. You may only see one arc above the dot if you are not receiving a good enough signal.
