Oooooh I have some ideas! Some of these are paid/premium (but NOT micro transactions) and some have mild ads. But I share the distaste for data-mining, money grubbing, brain-melting-ad-ridden games, so I'm certain they are on the least intrusive end of the spectrum.
I really love biology (I'm a biologist...) so these are both pet games and usually breeding/evolution games!
- Fish Tycoon -- This one specifically. A classic! Breed and care for cute fish!
- Niche breed and evolve -- so neat and pretty educational about evolution/genetics. There's a slightly more complicated/difficult pc game if she decides she likes the nichelings/universe.
- Pocket Frogs -- Simple, low stress collecting game. it would take years to collect all the frogs, and there's a relatively active community of people who trade sets of frogs to other people to help them complete collections. Would be fun to play with her friends at school!
- Reigns Her Majesty -- a game about running a kingdom as a queen. When you die, you become your heir and retain some progress from your last lives. It doesn't fit the exact criteria you mentioned, but I think she might like it anyway!
Whack. The only thing I can think of is if your base activity level has never been low enough in that several year period, you might not know what it feels like to be completely sedentary by comparison?