Having learned from experience, I would rather have the bells and whistles on the machine than get to a point where I felt ready to try to whistle, only to discover that I couldn't because I didn't have the right equipment.
If your granddaughter is like me, she will jump into something and figure it out if she has the tools to begin with. There's nothing more frustrating than wanting to try something only to discover that your machine can't do it, you have to order a different foot, etc. If she is coming for a visit, why not spend some time with her in your sewing room teaching her the basics and then visit a few machine dealers. Once she realizes just how much fun sewing is, I bet you might be surprised at what she can accomplish. I bought a dressmaker machine, because that's what I had always used my machine for in the past. Now I'm a quilting fool! LOL