Trying to find a sci-fi book I read in middle school.

So basically, from what I remember, this book starts out on earth with our main characters (a girl and their younger brother) hiding from aliens who are abducting people.

I forget how exactly they are caught, but i want to say they were hiding in a supermarket or warehouse. Once they are caught, they are taken up into the air where a decision is made via an alien pointing in either direction.

The next part i remember is that they are imprisoned and forced (via mind control) to dig for these energy pearls (or crystals) that supposedly supply an infinite source of energy. These pearls are a major plot point and are frequently brought up in the book.

On this planet, they meet some other dude (alien, i think, maybe originally a resident of this planet. I'm pretty sure he gives background info on this planet.) I remember their solution for escaping this mind control is to not fight it, but intentionally go along with it but make sudden movements in hopes of collecting pearls in between their toes hoping that when they are hosed down they remain stuck.

Eventually, their plan works out, and they somehow escape.

I don't remember how they get their own ship, but they make their way to some sort of "safe zone" where their wounds are treated at a clinic.

While they are here, they see everyone as their own race. The girl and the alien dude have the hots for each other.

Somehow, they get in trouble and are running. Alien dude throws a pearl at another pearl to create an explosion.

In the end, they end up in alien court, where they are to defend themselves.

I've been trying to find this book for a while now, yet I have come up with nothing. I remember loving this book, rereading it multiple times. Would love to take a look again.