My father was in the National Guard during 2 war times. We're having trouble getting Aid and Attendance for my mother. Suggestions?

Yes, what Florida said. Seems the National Guard is different than active service in the Army, Air Force, Navy and Marines.

"Persons in the Reserve or National Guard are not full-time active duty military personnel, although they can be deployed at any time should the need arise."

Maybe this will help;

https://veteransfinancial.com/veterans-benefits/reserve-and-national-guard/

Did they send your mom any correspondence?  I read this -

Army National Guard Service members on State Active Duty are not eligible for VA Aid and Attendance and Housebound Pension Benefits.  
For more information regarding eligibility see the VA web page about VA Pension


https://myarmybenefits.us.army.mil/Benefit-Library/Federal-Benefits/Veterans-Affairs-Aid-and-Attendance-(AandA)-and-Housebound-Pension-Benefits?serv=123

My father was deemed over income for A&A and his income wasn’t very high. Could that be it?