A 28-year-old primigravida at 32 weeks of gestation presents to the antenatal clinic in a rural primary health centre in Uttar Pradesh. She reports no antenatal care visits so far. On examination, her blood pressure is 160/110 mmHg, she has 3+ proteinuria on urine dipstick, and her reflexes are brisk with ankle clonus present. The health worker informs you that the nearest tertiary centre is 80 km away. According to the RCH (Reproductive and Child Health) guidelines for management of severe preeclampsia in resource-limited settings, what is the most appropriate immediate management?