Luckily, Mum has registered for antenatal care at your hospital and you are able to arrange for her booking bloods to be tested for Varicella-zoster virus Immunoglobulin G antibodies (VZV IgG). The results are likely to be back in 24 hours so you arrange follow up with maternity services tomorrow. She is anxious about the result and wants to know the next steps.
Which is the most likely?