Babysitter (Niece) received 5071c letter. Never Filed A Return

My niece watches my two kids some days to help us out while we work. I claimed this amount (roughly $2,500) when I filed my return. This was her only income and well below the $12,550 minimum so she didn’t file a return. Today she received a 5071c letter asking her to verify her ID because the IRS suspected someone used her info to file a fraudulent return. Could this be a result of me listing her on my return or something else? It says failure to verify could result in a delay of her receiving her refund (which she won’t have) and I’ve already received my return. Just trying to see if this is because of me or if someone got ahold of her info.