What does she want to do with a .410? Unless she wants to hunt, the .410 is kind of an odd duck for recreational shooting. Ammo is a bit pricey, unless you setup to reload.
If she wants to seriously move forward and develop her shooting skills...a rifle in 22LR and lots of Wally World 525 round value packs. And then off to the range with a stack of paper plates, tin cans, etc.
I'm partial to Marlins because they tend to be the most accurate out of the box, but a Rossi single shot (in combo with the 410 or 20ga barrel), a Ruger 10/22, Savage 64 or 93, Remington 597, Henry, Mossberg Plinkster, etc. are all great for building skill.
It's always fun to bring a trunk full of guns to the range for different shooting experiences, but truth be told, if all I can bring is a 22 rimfire rifle and a box of 525 rounds, I'm happy as a clam.
P.S. Dick's Sporting Goods has the Rossi 22LR/20ga combon on sale around here for $89 after rebate. My son Zachary has one for his squirrel rifle, and it's really quite a good setup. He doesn't shoot the 20ga much, but the 22LR has got great fiber optic sights on it, and is a lot of fun to shoot.