i have had a 10 year history of thyroid problems and unless its thyroid cancer it is actually quite controllable and you can be pregnant and taking medication to control it whilst being pregnant,you just need to be monitored regularly.i get checked every 8 weeks and i have have had radiocative iodine(like chemo) and a full removal of thyroid,she needs a referral from her gp to see a endocrinologist,but terminating is the 1st ive heard of it,if she really overactive,ie sped up metabolism,weight loss etc there is a risk of miscarriage but if you get onto it quick and get medicated theres a minimal risk..
hope ive been some help,also might be worth contacting the thryoid foundation australia,they are a great source of help
Cheers Bon