Is the money remaining from a business deal with a neighbor, who was later found to be dealing in usury and went bankrupt, lawful or unlawful?

So long as the woman was not trading, but rather taking people's money and engaging in usury, she is liable for the money she took from them. The questioner is only entitled to their original capital. If what they previously took under the guise of profit was less than their original capital, then they may take the remainder of their original capital without the increase.