Is there any reason to put 2 GFCI outlets in a 2-gang outlet box?
As long as the second standard receptacle is correctly connected to the GFCI receptacle as well as properly labeled with the usual "GFCI Protected" sticker, it should be acceptable for code.

The downside is it will look awkward and you should think more about if saving the small amount of extra money for an additional GFCI receptacle will be worth it.