Does my daughter's thyroid level warrant a follow up?

Hi doctor,

My daughter is 17 years now. We took her to ER for joint pain. Her joint pain started in the lower back three days ago and within a day, it was in all of her joints. But, there is no rash and fever. Two doctors saw her in the ER said that she needs further testing apart from laboratory tests. They ordered an ultrasound of her thyroid and suggest an MRI of thyroid depending on the ultrasound. They did not think she had a virus and referred us to a third doctor. The third follow up doctor believes that she has Parvovirus B19 (it is going around in her school) and nothing to bother following up on her laboratory reports or with the thyroid. Her TSH is 5.12 U/mL, and anti TPO is 19.15 IU/mL. Parvovirus B19 blood work showed IgM antibodies are 5.0 (negative) and IgG antibodies are 138.8 (positive). Other laboratory reports that are out of the normal range are red blood cells 5,520,000 per cubic mm, hemoglobin 15.6 g/dL, hematocrit 46.7 % and CRP 0.76 mg/dL. Do her thyroid tests warrant a follow up to check for hypothyroidism? Does her Parvovirus blood work indicate an ongoing infection or does it indicate an immunity? Many thanks for any advice on how to proceed. I have other laboratory reports, but I only included those outside the normal range. Thank you.

Thank you doctor,

I did not realize TSH could vary depending on time of day and age, so that is very useful to know. My grandmother had overactive thyroid and was very underweight. Other than that I am not aware of any thyroid issues in the family. Are there any nutritional supplements my daughter should take to protect her thyroid and make sure her levels are good? I read that Selenium is good for the thyroid. My daughter constantly follows the diet and do exercises and struggles to maintain normal weight. Despite this, I was told that her liver was fatty last year. Thank you very much for your help.