I don't think Andromeda's rebellion was loud, like Sirius'. Not really.
I think Andromeda was a Black through and through. Her parent's pride: Slytherin, prefect, first of the class. She followed the rules, and she knew what her name entailed.
Andromeda Black used to scorn at muggleborns, to mumble stray "mudblood"s when the occasion was fit.
That's how her and Teddy first met. He and his Hufflepuff friends tripped with her, her books fell on the floor, just like a meetcute. But Andromeda didn't blush, she didn't feel like the protagonist of a romance movie.
She saw red. This careless Hufflepuffs had ruined her books, there was spilled ink all over her pages, and, worst of all, there wasn't a single pureblood amongst them.
Maybe she had already been having a bad day. Maybe, in any other situation she wouldn't have reacted, she would have been prideful.
But she cursed them out. She let out a long string of slurs that weren't even in use, a "this is what happens when they let fucking impure thieves into our school", etcetera, etcetera.
And she got a book to the face. Square, right in the middle.
Ted Tonks, one of the Hufflepuffs in the group, had grown tired of her racist rant, and had decided to put an end to it. The muggle way.
Hell ensued: Andromeda brought out her wand and started cursing. Ted charged at her with his bare hands (he was trying to prove a point). The rest of the Hufflepuffs scattered.
The teachers didn't take too long before they arrived and separated them, but Andromeda Black already had a black eye, and Ted Tonks had some ugly, bloody gashes where her curses had landed.
And they were forced to do Detention together.
They couldn't stand each other, from that point onwards. Until Andromeda started changing.
I don't think Andromeda's rebellion was loud. I think it was slow. I think she had to unlearn everything her parents had taught her, and I think at first she wasn't willing. But she was, eventually.
And she did change. She became better.
