I was about to say the same thing

In addition to the info given by chillmog, I add that your mother might not want to use a mobile device, especially if she is used to watching tv a lot and does not leave the facility frequently... you might consider getting her a "smart tv" rather than a tablet or laptop. Does she like to watch movies that she can access from Netflix or Blockbuster or even Hulu using the "smart tv"?
Her personal interests will dictate if she would like to tweet or use facebook using a computer.
I suggest a cheaper tablet for her at first rather than a recent new generation iPad that has a faster processor and a lot of memory. She might drop the tablet or other device so a cheaper tablet might be considered. If she has good reading vision, you might want to start her on a smaller screen and then get her a ten inch one if that seems desirable.
You might take her a laptop with Skype installed with a web camera to see how she likes interacting with others who have Skype capabilities.
For safety and convenience, you could buy her a cheap prepaid phone with no subscription required for her use mostly away from her living facility.
Everyone is different in interests and competencies. My 59 year old daughter is proficient at the intermediate level in using a p.c. and work-related software. My 57 year old son is an advanced computer programmer and data analyst. My 52 year old daughter is overwhelmed beyond a very basic use of her p.c.
I am 77 and love to use desktop and laptop computers to connect to the internet to keep up with "what's happening" related to computers. Fast connectivity is very important to me.