I think she should get tested for
thyroid anti-bodies, which are found
in hashimotos,
thyroid disease, especially with her swinging from hyper to hypo, it may be hashimotos,
I would get her FT3,FT4,TSH and antibodies checked, she might need more throid hormone, her body might not be getting enough, at this crucial time in her life.
I wish you both well and hope you can sort this mess out for
your wife,
Take care, keep me posted.