Hi, we are both in the "70" plus age group, and both have a Toshiba. No problems with keyboards, mine is  15.6, Hugh's is 17", and the bigger screen might be better. I would get as much RAM as you can, as they might use it more than you think,Will there be any problems with both wanting to use it at the same time?? And can they get Broadband where they live?
Library books online, shopping specials, trademe,  weather, Geonet, all these and more  can be so important to any older person who might not get out so much.  Skype and emails too, the other thought is get a separate keyboard, wireless, with a  wireless mouse, do they have room for this or will it be used on a table, or a desk?I'm sure this will be so much used, and they will be ever thankful. Cheers, Nancyjj