Editing to spoil this, because it is completely unsolicited comments/opinion based on what might have been a very different situation.
Spoiler
... I can't help thinking that her daughter might actually be better off in the system than with that kind of an example in front of her.
More relevantly, since your brother's sons are her brothers, I think your brother can, as guardian for them, register them as family who want to keep up relations.
Technically the two boys would have to pass a background check.
They're minors, I'm SURE they will pass. >.<
So even if he doesn't get her directly, he should still get visitation rights by proxy (because the boys, as siblings, would have family visitation rights with her so long as he fights for it on their behalf, which he *would* have the right to do).
it's something to talk about, with someone who would know your local system.
For sure it works that way here, but I think that might fall under a state-by-state thing.
One of my cousins had drug problems, and she had three children by two different fathers, and we went through something similar. She's doing really well at this point in time, but it's been a while. Her oldest is already graduated and off on his own (he's gone military because he wants to be an engineer and they'll cover his schooling costs. There were a lot of tears about it, since military is not exactly the safest choice you can make) and her two youngest are permanently awarded to their father, so she only gets visitation. She says though that she's glad they had a better example than she was being, so.... that's the only example I have, and while the process at the time was pretty miserable, I will say that nearly everyone in the both families assert it was worth it.
ANYHOW!
I am glad your shopping trip was so productive! And too big is probably a very good thing. It's funny how fast kids grow, ha ha! Shoes that light up, eh? Sounds snazzy. And very safe for walking at night, such as for Trick-or-Treat. Was she wanting those before, or did you kind of act super excited about them until she wanted them, because you wanted her to have them?