My wife has pregnancy thyroid but it was detected after 5 months of delivery. is there any chances of being this disease finished?

Possible : It is certainly possible but not very likely. The easiest thing to do is to have the hormone level rechecked. Your doctor should be able to do this easily.

Possibly: There is a disorder called post partum thyroiditis. This can cause thyroid levels to be temporarily abnormal, and may return to normal within 1 year after pregnancy. However, there are other more permanent thyroid problems that also develop after pregnancy, that do not resolve. Getting thyroid antibody levels can help to decide which problem she has.