Depends on the intended usage. Personally I find an iPad (or any tablet) to be more of a toy than in comparison to a laptop. That is mostly due to the fact that with a laptop running Windows I can run the same types of programs as on my desktop. Additionally, should I want to play games the games I purchase for my desktop can technically be played on the laptop as well. However, playing games on a laptop means lowering game settings to get decent / good performance since graphic cards for laptops are weak in comparison to their desktop counterparts.
iPad / tablets are good for consumption rather than productivity. Consumption includes watching video, surfing the net, typing the occasional e-mail, play some simple games (compared to more complex types of games on a PC; generally speaking), listening to music. I'm sure there are plenty of other things it can do...
While it is possible to be productive using a tablet, it is also very limited in my opinion. For example, using a tablet to type a quick e-mail is one thing. Using it to write a term paper is quite another; yes it can be done if you have no other choice, but a laptop is more ideal. You can use it to track appointments. I'm sure there are some other productive things you can do with an iPad/tablet, but since I don't own one, I suppose I will never find out.
Make your choice based on what your mom wants to do with a "portable device".