Thanks Zaap!
Eug...Is there an equivalent MacBook to those specs? She's just 12 but the mobility of a laptop might be nice.
At just 12, a used white MacBook C2D MY2010 would be OK. She'd use it for a year or two and then you'd know if she'd need or want something better. I bought one about a year ago for $200 from Craigslist; now they should be less. I added a 128GB SSD (trivial... takes a screwdriver and 15 minutes) and 9GB of RAM (about $100) and it was able to network-boot to the internet, download the right OS, and install and upgrade itself appropriately to the very latest and greatest.
Without the SSD, the process would've been painful. With it, it was fine.
Of course, if you can, getting an i3 or i5 CPU is a far faster and far better base machine. It's worthwhile to do so also due to the longer supported lifespan - new OSs will soon drop support for anything before the i3/i5.
I have an 11 year old (with the 2009 Macbook with 4GB and 128GB SSD) and a 17 year old (with the 2010 Macbook with 9GB and 128GB SSD) and they're both happy with the machines they have. Sure, they'd love a shiny silver something to show off at the local Starbucks (well, the 17 year old; the 11 year old couldn't care less) but both machines are perfectly functional. Note that the main use for the 17 year old is chatting in iMessages with her friends, and for the 11 year old, watching YouTube videos he doesn't want the adults to see and watching video files he gets from friends.