At that age I highly recommend local CL buys if you can find them. In my area kid boards are always being listed at big discounts because they have been outgrown. My son was going through a complete new setup each season. You have to get boots, boards and IMO.
If you want a new board try this site: Buy Snow online snowboard pro shop has snowboards, snowboard binding, snowboard boots and snowboard clothing from burton, volcom, roxy, dc, vans, 686, rome, lib tech, never summer, and more for all your snowboarding needs.
Great deals on new boards. The Feelgood board is a nice board but I'm not sure it'll fit her weight. You'd have to check that out and see but I think it starts at 80 or so pounds recommended weight.
If her shoe size is on the lower end of a binding size you might want to spend your money on a nice set knowing she won't outgrow them for a few seasons. I really love my Lexa bindings and you can find a lightly used pair of smalls for under $50 on Ebay.
I have no idea on the best boots since it varies so much person to person.
For kids I recommend pants with adjustable waist straps (velcro adjusters). I also suggest light/medium weight pants a size to big that they can wear layers underneath. Next season those "one size to big" pants will be great in the spring or on warmer days before they are completely outgrown. My son wore Ripzone and Toma's when he was outgrowing things fast. It was nice gear that lasted an entire season and a friend's kid has worn those same pants for two seasons now w/o tearing them up. Nothing fancy, but very effective.
Hope this helps a little.