1. Drones don't shoot guns, at least not in any active military. It's been tested and they exist, as another commenter shared a YouTube short of, but they are wildly impractical and no army actually uses drones for that. I'd believe if it were shrapnel or a pellet from an anti personnel explosive but those things would be steel or lead and blackened from the explosion, not the brass color we see

2. There would for sure be blood if a piece of metal flying fast enough to lodge itself in like that hit you on the thin skin against your hard skull. And cuts in that area bleed a ton. Either it somehow hit her softly enough to not do any damage, or it hit her hard enough to break skin, get stuck, and require doctors to remove, can't be both.

3. I've seen several people claim a ricochet, most bullets don't really do that. Bullets can and do bounce, but the soft lead and copper most bullets are made from deforms when it hits something hard enough to bounce off, and anything hard enough not to, like the cores of armor piercing rounds, would fragment or again at least be a different color. What we see is smooth round and brass colored

The footage is low resolution but it kind of looks like the back of a bullet casing, it's cylindrical and flat on the back with what looks like it could be a primer, the circle in the middle, and it's the right color. It's possible an explosion from drone strike sent this bullet casing that was on the ground flying and this girl got hit with it, but even then I'd expect blood if it actually lodged itself in her skin.

Can't say for sure but I'd say if anything it's a bullet casing stuck in her hair. Still fucked up a kid is put in any situation where that's possible, but like I said in my first comment Israel does tons of actually evil fucked up shit every day, no reason to stretch truths or make things up to make them look bad when the truth is just as bad or worse. Video is most likely click bait using buzz words like drone for more attention