(Thanks to Fire Emblem Wiki for this)

Born in the Sacaen Plains, Lyndis's parents, Hassar, chieftain of the Lorca tribe, and Madelyn, daughter of Lord Hausen of Caelin were killed by bandits before the beginning of the FE7 game. She was named after her maternal grandmother. She lives alone until she finds a tactician (the player) lying on the ground. Upon meeting him or her, she decides to follow him or her in the interest of training her sword skills.

Lyndis decides to stop at a nearby town to resupply, but is confronted by a horde of mercenaries led by the brigand Zugu, but they are disposed of by Lyndis and the aid of Sain and Kent, knights of Caelin who tell her that she is the granddaughter of Lord Hausen, the Marquess of Caelin, who wants to welcome her into his home (something he had refused to do when his daughter Madelyn) eloped with a Sacaen "savage").

Ok, that should do for Lyndis's background. For more info., please go to: http://fireemblem.wikia.com/wiki/Lyndis/. 

Now, for her stat info. Lyndis's Skill, Speed and Luck OWN. Oh yes, she DOES have moderately good Resistance, as well. Her Strength still hurts a lot though, which is why she cannot kill enemies in one turn all the time. Plus, she can use Bows after promotion. Sweet, right?