I would see a pediatric endocrine specialist. Her Free T4 levels are low which will cause her to have hypo symptoms. The new TSH range is .30-3.0 so she is already bordering that as well...besides, TSH is a pituitary function test. Free T4 and Free T3 are the active forms of thyroid hormone with the T3 being the most active. She needs to have a proper ratio of both, as the T4 gets converted to T3.
Over 8 years ago the AACE recommended that the range for TSH should be revised downward to .3 - 3.0. Unfortunately most labs and doctors have not adopted the change. Even though TSH is a pituitary hormone that is affected by many variables to the extent that it is inadequate as a sold diagnostic for thyroid, it is an indicator, to be considered along with more important indicators such as symptoms and also Free T3 and free T4.
Your daughters TSH is slightly indicative of the possibility of being hypothyroid. Also, the Free T4 is below the range, which is another indication. Even though her Free T3 is just slightly below the middle of the range, the range is also too broad. Patients with Free T3 and Free T4 results that are in the lower half of their range frequently have hypo symptoms.
I know she is young, but if you look at this list of 26 typical hypothyroid symptoms, does she seem to have any of these? If so, that would be a further indication.
It is very good that she has been tested for Free T3 and Free T4 since those are the biologically active thyroid hormones. Free T3 is the most important, because it largely regulates metabolism and many other body functions. Scientific studies have shown that Free T3 correlated best with hypo symptoms, while Free T4 and TSH did not correlate at all.
I think it would be a very good idea to push for seeing a good thyroid doctor. That does not automatically mean an Endo only. Many of those specialize in diabetes and not thyroid. Also many others have the "Immaculate TSH Belief' by which they believe they only need to use TSH to diagnose and treat a thyroid patient. Others only want to rely on "Reference Range Endocrinology" and will tell you that a test result that falls anywhere within the range is adequate. This is not correct because the ranges for FT3 and FT4 are far too broad, since they have never been corrected like was done for TSH over 8 years ago.
When I say good thyroid doctor I mean one that will test and adjust Free T3 and free T4 as necessary to relieve symptoms, without being constrained by resultant TSH levels. Symptom relief should be all important, not just test results. Finding an Endo that is also a good thyroid doctor is the best of all worlds.
You can get some good insight into clinical treatment from this letter written by a good thyroid doctor for patients that he sometimes consults with from a distance. The letter is sent to the PCP of the patient to help guide treatment.
I know that you are in Canada and that it is often very difficult to find a good thyroid doctor as I described. I also recognize that I have laid a lot of info on you all at once. I am just trying to impress on you that it is important for your daughter to find a good thyroid doctor.
One of the best ways is to ask around if anyone has any recommendations for a good thyroid doctor. You might also ask your local pharmacies if they can tell you of any doctors that prescribe Erfa Thyroid, which is a combo T4/T3 type. Generally we have found that any doctor that prescribes these meds is usually the type willing to treat clinically. Lacking any luck in finding a good thyroid doctor, you might be successful in working with your doctor by giving information like some I have provided above and influencing treatment that way.
Don't let any of this alarm you. I am just suggesting that you should go ahead now and start looking for a good thyroid doctor that she will surely need in the future.
One thing I would go ahead and do now is to get her tested for the thyroid antibodies. Those tests would be TPO ab and TG ab. They are used to test for Hashimoto's Thyroiditis, which is the most common cause of hypothyroidism. I also suggest that if she already has some hypo symptoms, then it would also be a good idea to try to get her started on thyroid meds, to prevent any possible effect on her impending, normal hormonal changes.
Poor thing! That must be challenging for a little girl. Is she taking medication? I have heard low thyroid levels can interfere with proper growth, so I would almost think it'd be more important to seek good treatment for a child. Not to mention she may be having problems paying attention during school or staying active. Specialized treatment could help prevent many emotional, weight, and education that may only become more complex as she goes through additional hormonal changes during the next few years. Hope she feels better soon!
I have a 16 year old daughter who's thyroid levels are also being watched. I won't get into her levels because I don't want to turn it into a discussion about her. For a time we are not doing anything about the thyroid as we are getting her POTS under control and she is doing very well. For her increasing her ferritin levels (were way low inspite of having iron rich foods) and with being on fludrocort (cortisone) her thyroid levels are now looking normal but she will continue to be regularly monitored. She also does not have hypothyroid symptoms. I do wonder if she will go onto having thyroid issues and like you was wondering if more should be done. Sometimes looking at other levels outside of thyroid like iron/ferritin panel, the different vitamin levels, etc. might be a start in helping support good thyroid health. I did come across this article: http://www.thyroid.org/professionals/publications/clinthy/volume23/issue12/clinthy_v2312_2_3.pdf
It is listed from the American Thyroid Association and addresses pediatric hypothyroidism. Adolescent and children needs in general are sometimes addressed differently but I agree that careful monitoring is important especially if they are presenting with hypothyroid symptoms or tests indicate a valid issue.