Dynamite? Probably a large flash-powder firecracker, especially if it had a fuse protruding. Real dynamite needs a cap and fuze, and would not be put into long term storage with a cap.
A quarter stick of real dynamite would do more damage.
The “quarter stick” firecracker held 10 grams of flash powder, nothing to mess with, but nowhere the power of dynamite.
My first thought. Real Dynamite would not have just damaged her hand, it would have killed her.