getWife method
Returns the wife/mother of the family
Returns null if not found
Implementation
IndividualElement? getWife(Map<String, GedcomElement> elementsMap) {
final wifeId =
children.firstWhereOrNull((element) => element.tag == GEDCOM_TAG_WIFE);
if (wifeId != null) {
final wife = elementsMap[wifeId.value!];
return wife as IndividualElement?;
}
return null;
}