I think it's great! I think just add a bit more action after the things they say. For example (you can use any and all of the following examples throughout the entire thing if you choose to do so)
"A trial." My dad said, dodging her eyes.
This is more advanced because in certain circumstances this would be a bit too much, but I think if you want to keep the energy/tone of the scene up without sounding repetitive with too many extra-descriptive words, then this is an excellent way to do just that.
Another advanced technique: Play around with the ordering! If it's going to be straight dialogue, change it up! Here's what I mean:
*“She's going to stay with us for a while if that’s ok. The Council voted to keep the investigation open, and I believe that Alya and I need to stay away from Alex or the Council will never drop the investigation.”
She presses her lips together before barking, “You may be in all technicalities, her brother, Ben. But I’m pretty sure that this as good as kidnapping. I’m not helping you get into trouble with Southwater authorities, when the Council of the Fairies already has a case on you,”
"We’ll do it the legal way then. I’ll do what Elena did with you.” my dad counters firmly.
Mom seems just about done with him. “You can’t file for guardianship, Ben.”
“Why not? Alex is a criminal, a traitor, an outlaw, a fugitive among other things. Alex has no legal way of fighting it.” He folds his arms mulishly, not backing down.*
I don't know why, but I think of this as spicy writing, not necessarily like ouch, spicy or 😏spicy but tasteful, colorful, advanced, you know? Also, it's really hard to find a good balance without making it overpowering or too bland. I'm sure I've overdone it in the majority of my writing, so I'm not as reliable to help you find that balance, but it's a touch-and-feel process. You do what you feel is good, write it like that, and then take a break for a bit. I know, it seems a bit strange. Trust me on this, your eyes will never be clearer. If you've already done this, then you know what I mean. If you haven't, then get ready to feel it all.
And if you're still struggling with the balance, you can ask me and I can share with you a chapter or two of my writing (but privately, and only if you really need a basic guide) so that you can understand a bit more of what you can do, what the limits are for how you play this (at least how I see them so far. My works are all works-in-progress too 😅) and maybe recognize a bit of yourself in my work (I've noticed that we write very similarly and I think it's awesome). But, you do not have to do this. Trust yourself first. I'm not any more advanced than you are, I just recognized a few things I needed help with at one point in your writing, just like you might recognize a few things in mine.
Sorry, my things are always so long, but anyway yeah. Those are my recommendations.