As I see it... if you can get VA disability dependent pay for your Asawa and biological children (which you can) then she and children should get survivors benefits regardless of nationality. You just have to die of a service connected disability or be 100 % disabled for a period of time before death.

 

Yes.

There is also a "survivors pension" available if the widow meets certain income requirements.
https://www.va.gov/pension/survivors-pension/