It would be an understandable reaction for husband (and the whole family) to use the nuclear option. But I’m not sure I would. If I did try to confront, I’d suggest a nuanced approach. Maybe have husband ask when the package arrived because daughter was home all day and looking for the package. 'Thank you, by the way, she put it to use right away.'

That would give husband an opening to bring up the subject of ignoring you, and neighbor an opening to reveal her true thoughts, or, possibly, soften. I don’t suggest this to protect the neighbor, rather because this is someone living right next door. Could it get worse, ie: aloof racism vs. open hostility?