Method to Acquire: Starts with you on Chapter 6 with Saul.
Damage: It's not so good in the beginning but it gets a lot better. She'll usually max out Strength.
Critical: Bereft of her supports, Dorothy's critical isn't very high and there aren't any bows that increase critical hit rates.
Speed: She's probably going to be hitting once when you get her and twice after you level her up.
Dodge: It's pretty pitiful to start. You have to protect her heavily in the beginning if you plan on using her. She averages 64 dodge as a level 20 Sniper, which isn't that bad.
Growth Rates
HP - 85%
Strength - 50%
Skill - 45%
Speed - 45%
Defense - 15%
Resistence - 15%
Luck - 35%
Average Level 20 Sniper Dorothy
HP - 53
Strength - 23
Skill - 25
Speed - 24
Defense - 11
Resistence - 9
Luck - 16
Total - 161
Supports
Saul - 20/30/40 turns
Percival - 59/60/80 turns
Yodel - 10/30/40 turns
Shin - 59/60/80 turns
Clarine - 59/60/80 turns
Rating: 8.1/10. Wolt should be higher levels then her by Chapter 6 and Klein is better then all Snipers on Hard Mode. Unless you like her, and I can't see any reason why you would, don't use her. Unlike Fire Emblem 7, Anima-magic users can also deal high damage to flying units so Archers/Snipers lose some of their charm.