Method to Acquire - Speak to her with Roy in Chapter 6 once she pops out of the bottom right corner of the map, speak to her in Chapter 8 after she comes out of the right set of steps with Roy, and finally speak to her in Chapter 12 with Roy a final time once she comes out of the top of the map. If you missed one conversation, you have another chance to speak to her on Chapter 16. Remember to steal her Lockpick in Chapters 8 and 12 before she runs off the map.
Damage - Her damage is pitiful. She has the worst strength gains out of Fire Emblem 6 and 7.
Critical - It's not very impressive unless you decide to waste a Killing Edge on her. Get her supports with Geese for a good laugh.
Speed - She's the speediest thief there is, and she will no doubt max speed by Level 16.
Dodge - She has high luck as well as high speed, making her the best dodging thief there is.
Growth Rates
HP - 80%
Strength - 40%
Skill - 45%
Speed - 85%
Defense - 15%
Resistence - 20%
Luck - 50%
Average Level 20 Thief Cath(Hard Mode stats in parenthesis)
HP - 28(32)
Strength - 9(9)
Skill - 14(18)
Speed - 20(20)
Defense - 2(2)
Resistence - 4(6)
Luck - 16(19)
Total - 93(106)
Supports
Chad - 59/60/80 turns
Geese - 40/60/80 turns
Barth - 59/60/80 turns
Garret - 59/60/80 turns
Hugh - 59/60/80 turns
Rating - 8.45/10. While she may max speed the fastest, she also comes the latest and is the worst fighter out of all the thieves. She's alright if you arena abuse her, but even still she should only be deployed for treasure chests, doors, and stealing since she won't be dealing ANY damage towards the end of the game.