I'm new to the forums, and I've seen a few people mention nursing taking twice as long, or crops taking even longer to grow. I haven't seen anyone post why this happens, so if this is a "der" post - please forgive me.
I discovered that it is literal time, and is related to the speed of the game. I usually run it in 2x mode, but changed it to 1/2x to see what would happen and the time remaining to nurse for one of my villagers went from about 21 minutes to about 70 minutes.
Love the game, I'm only about halfway through the puzzles. :-)
- Moira