Hi!
You can't lose the farm in
A Wonderful Life. Sorry if my review gave that impression.
You could always try renting AWL for your sister and see if she likes it. (Our Blockbuster has it, which surprised me). If she's planting pumpkins and saving up for her own cow (aww!

), she may like that AWL is more like a "real" farm.
But if she wants something more like the SNES version,
Harvest Moon: Friends of Mineral Town for the GBA is pretty good. It's got the same overhead perspective as the original, and a lot of the same systems for fishing, growing crops and taking care of animals. In fact, I think it's easier to tell how much the animals like you in FoMT. There's a screen with a series of hearts by each of the animals' names. Plus, there's sheep
There's also
Harvest Moon 64, which is good but rare. I found a used copy at a flea market for $40.
Hopefully other HM fans will climb out of the woodwork and offer suggestions.
Tera