hello sir , Thyroid
problem is most common in women , as such ur wife had MRI
thyroid which shows benign tumour . Thyroid benign tumors called as goitre
as there is no need to worry until it is benign and her thyroid hormones are within normal level .
If its still causing worry about thyroid u can confirm it with USG Guided FNAC and by pathologt report u surely can confirm benign or malignant as remove ur untoward worry regarding the same.
Coming to the symptomd u mentioned might be non specific symptoms until ur thyroid hormones within normal limits