I have a defunct Princess Sparkle also; she is all rusted up and am guessing beyond repair unless anyone knows otherwise? :/
Maybe not! I mean, you might need to replace most (or all) of the parts, but with some ingenuity she could be fixable
From what I've seen of their mechanisms, they're quite simple to manipulate and anyone with a little small electronics knowledge can understand the components. So if there's a local shop that does repairs, or you know someone who's handy with this stuff, they might be able to suggest a solution for you, or fix the problem outright.