If it's 6- 8 hrs or more after eating before symptoms than its not an intoxication, but Staph food poisoning. Staph aureus is the most common cause of food poisoning. Hardiness a factor here. Beta hemolytic means complete lysis of RBC's on blood agar in lab. Only in the immunocompromised.
Rheumatic fever is a delayed inflammatory disease of joints, and heart.
Both of these conditions caused by too many of the antibodies that are formed by the 3rd line B lymphocyte response to the Strep pyogenes invader. These supposedly specific antibodies crossreact with self antigens and cause destruction of the body's own organs. Antigen-antibody immune complexes also circulate through the blood and are removed by the kidney but they are so large that they clog and damage the kidneys. Doesn't happen to everyone who gets strep throat or scarlet fever but not uncommon. That's what she died of.