Use the utility function

src/uncategorized/saRivalries.tw

@@ -244,7 +244,7 @@
 		<</if>>
 	<</if>>
 	<<if $familyTesting>>
-		<<if $slaves[$i].mother == $slaves[_j].ID || $slaves[$i].father == $slaves[_j].ID || $slaves[_j].mother == $slaves[$i].ID || $slaves[_j].father == $slaves[$i].ID || areSisters($slaves[$i], $slaves[_j])>>
+		<<if areRelated($slaves[$i], $slaves[_j])>
 			<<if _roll > 70 && $slaves[$i].rivalry < 3 && _lightenedRivalry != 1>>
 				$slaves[$i].slaveName and <<= SlaveFullName($slaves[_j])>> @@.lightsalmon;pursue their family rivalry.@@
 				<<set $slaves[_j].rivalry += 1, $slaves[$i].rivalry += 1>>