She also asks: “To what extent might it represent a threat to me or my husband?”

Your husband is at risk because you are at risk, and he could be a target for retaliation against you. It is not uncommon they will punish someone by harming a loved one. This retains their ability to continue manipulating the targeted individual because everyone else is expendable and simply a tool to serve their aims. This is not to say anything specific will happen, we are simply answering your question and the risks are there because of who they are and what they are capable of doing.