Granny Smith was instrumental in the founding of Ponyville. She and her family of pioneer ponies came to the empty land to build their first home. But food was scarce, so young Granny Smith went into the Everfree Forest to look for edible plants, and found a Zap Apple Tree. She picked as many apples as she could, but was then chased out of the forest by the Timberwolves. She got back to her house and started banging a pan against a cooking pot to wake everyone up and warn them of the Timberwolves. She and her family developed all sorts of recipes for Zap Apples, most notably, Zap Apple Jam, which they sold to other ponies passing through the area. Soon, ponies came from miles around and settled down in the same area, and the town of Ponyville was formed.
These days, Granny Smith is a well-meaning but often scatterbrained old lady, who often forgets things and doesn't do a lot of physical labor on the farm. Most of the responsibilities are Applejack's now. But she's always there to dispense wisdom and comfort (and stories) to ponies.
She is a member of a group of other grandmares called The Gold Horseshoe Gals (a reference to The Golden Girls).
Family Appreciation Day
Apple Family Reunion
The Super Speed Cider Squeezy 6000
Pinkie Apple Pie
Leap of Faith
Where the Apple Lies
The Perfect Pear
Grannies Gone Wild