My Wife Has Been Having An Increasing Number Of Headaches

My wife has been having an increasing number of headaches after eating. She's 77. But it doesn't always happen. Tylenol, claritin, benadryl, etodolac don't seem to have any helpful affects, only 1/4 or 1/2 tab trammadol. Her daily Rx meds include: 50 mcg levothyroxine, 37.5 mg (1 1/2 tabs) HCTZ, 50 mg atenolol, 1-2 tabs 400 mg Etodolac, 1mg Estradiol. Her blood pressure is really good - usually 120-130 over 70-80. The headaches are mostly in the frontal part of her head, never in the back. She is allergic to yellow 5 & 6 which the benadryl alleviates when the rashes appear. I'm stumped.