Sonam is walking facing north. She turns right

Why

Rishi's answer happens to be correct for this exact situation, which is probably why it feels like a general rule — but he is confusing a fact about ONE case with a rule that would hold in every case. 'Right' is not a fixed compass direction at all; it is relative to whichever way someone is already facing, and it always means turning 90 degrees clockwise from that starting direction. Facing north, a right turn does land on east — but facing east, a right turn lands on south, not east; facing south, it lands on west; facing west, it lands back on north. Test it: if 'right always means east' were truly a fixed rule, then someone facing south and turning right would ALSO end up facing east, which would mean they turned a full 180 degrees rather than a quarter turn — an obviously wrong result. His teacher is right: which compass direction 'right' points to depends entirely on the direction someone started facing — it happened to be east here only because Sonam started facing north.