Thanks for writingyour query.
After reading your post, I would like to mention you that she is overweight
and needs serious attention on this. You have also mentioned that she is having no issue. I hope you are not following any methods to prevent pregnancy.
Inability to conceive along with increasing weight is a common finding in thyroid disorder
. I suggest you to get the following investigations :-
1. Thyroid Profile
2. Lipid Profile
4. Serum Proteiin
5. Urine (Routine/Microscopic)
You should get her examined by a Gynaecologist for fertility
I hope this is helpful to you.