She bought it as a “second home.” It just had to be “primarily available” for her use within the first year. After the first year my understanding is she can do whatever she wants with it, and even within the first year rentals are explicitly allowed. And if she visits her family member that lives there, that likely counts as using it.
I thought this was a good article summarizing it:
https://www.lawfaremedia.org/article/the-justice-department-s-dangerously-weak-case-against-letitia-james
And a recent development is that Halligan apparently reached out directly to someone else from that outlet, who simply summarized an NY Times article, and Halligan repeatedly told her she was wrong but refused to specify what was wrong.
https://www.lawfaremedia.org/article/anna--lindsey-halligan-here