I live in the Middle East and fly regularly between the US, Europe, and Middle East. In my opinion it really depends on the amount of time and cash.
If you have time and would like to add another destination on to your travel now is the best time. You can fly into one of the main hubs in Europe and take a couple of days to relax. This cuts your flights down into manageable chunks in the cattle car section. Good stops at the major hubs include Amsterdam (KLM), Frankfurt (Lufthansa), Paris (Air France), and London (British Airways). Our favorite as a family is Amsterdam.
If time is an issue then it can be worthwhile to pony up the cash for business class tickets. Maybe just buy one business class seat for your 85 yr mother. Having the ability to have your seat completely recline flat is a lifesaver on flights that are longer than 8hrs. Some airlines have economy plus which isn't bad if you can get bulkhead seating.
Typically on family vacations we stick to having a 2-3 day stop over in Europe to just get off and move around. The break up helps a lot, especially with younger kids and older parents. Plus there is so much historical places to visit. We have one set of parents coming over this fall and we set them up to layover in Istanbul (It's actually a pretty amazing place), before coming to us.