I think I solved it myself after some searching on this forum.

void receive(const MyMessage &message) {
Serial.print("Receive.....");
if (message.type == V_VAR1) {
      if (message.sensor == 1) {
        pulseCount = oldPulseCount = message.getLong();
        Serial.println("Received data from child 1: ");
        Serial.println(pulseCount);
    } 
      else if (message.sensor == 2) {
        pulseCount2 = oldPulseCount2 = message.getLong();
        Serial.println("Received data from child 2: ");
        Serial.println(pulseCount2);
    }
  pcReceived = true;
  }
}