Vomiting UTI Treatment tablets full tabs

My mother, around 50, has type 2 diabetes, hypertension and mild CAD (no stent/heart attack). She has painful, frequent urination and visible blood in urine. Culture: E. coli >100,000 CFU/mL, sensitive to nitrofurantoin and cotrimoxazole. USG suggests cystitis, no stones. Creatinine 0.75, Hb 10.2, WBC 12,400, HbA1c 7.3%. Medicines: UriBID 100 mg, Bactrim DS, Gluconorm G1 Forte PR, Rejunex CD3 NF (half tablet), Rosuvas-F 10 and Telma 20. Ecosprin-AV temporarily stopped by doctor. She has vomited on two consecutive days, including food and a white tablet-like object. If taking tablet around 8 am and afternoon 2 pm vomited 2 tablets came just like original if I pressed turned into powder form. She also has stomach pain and headache. Previously tolerated another nitrofurantoin brand. Was the morning medication likely absorbed? Whether body rejected medicines?