ExtBase localization of child records

DataHandlerHooks.php

<?php
namespace Vendor\Product\Hooks;

use TYPO3\CMS\Core\DataHandling\DataHandler;
use TYPO3\CMS\Core\Database\DatabaseConnection;
use TYPO3\CMS\Core\Utility\GeneralUtility;

class DataHandlerHooks {

	/**
	 * @var DatabaseConnection
	 */
	private $dbh;
	
	public function __construct() {
		$this->dbh = $GLOBALS['TYPO3_DB'];
	}

	public function processDatamap_afterDatabaseOperations($status, $table, $id, &$fieldArray, DataHandler &$dh) {
		//$a = 1;
		if ($status == 'new') {
			$realId = $dh->substNEWwithIDs[$id];
//			$incomingTable = $dh->substNEWwithIDs_table[$id];

			foreach ($dh->remapStack as $remapStackItem) {
				if ($remapStackItem['args'][$remapStackItem['pos']['tcaFieldConf']]['foreign_table'] == $table &&
					$remapStackItem['args'][$remapStackItem['pos']['tcaFieldConf']]['type'] == 'inline'
				) {
					$languageUid = $this->dbh->exec_SELECTgetSingleRow(
						'sys_language_uid',
						$remapStackItem['args'][$remapStackItem['pos']['table']],
						'uid=' . intval($remapStackItem['args'][$remapStackItem['pos']['id']])
					)['sys_language_uid'];

					$this->dbh->exec_UPDATEquery($table, 'uid=' . intval($realId), ['sys_language_uid' => $languageUid]);

					$fieldArray['sys_language_uid'] = $languageUid;
					$dh->checkValue_currentRecord['sys_language_uid'] = $languageUid;
				}
			}
		}
	}
}
?>

ext_localconf.php

<?php
if (TYPO3_MODE === 'BE') {
	$GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['t3lib/class.t3lib_tcemain.php']['processDatamapClass'][] =
			'EXT:product/Classes/Hooks/DataHandlerHooks.php:&Vendor\Product\Hooks\DataHandlerHooks';
}
?>

Parent.php

<?php
namespace Vendor\Product\Domain\Model;

class Parent extends AbstractEntity {
	//
	// class attributes go here...
	//
	
	/**
	 * @var \TYPO3\CMS\Extbase\Persistence\ObjectStorage<\Vendor\Product\Domain\Model\Child>
	 * @lazy
	 */
	protected $children;
	
	/**
	 * @var \Vendor\Product\Domain\Repository\ChildRepository
	 * @inject
	 */
	protected $_childRepository;
	
	
	//
	// class methods go here...
	//
	
	/**
	 * @return int
	 */
	public function getLocalizedUid() {
		return $this->_localizedUid;
	}
	
	public function getChildren() {
		// TODO: check inconsistence here, since $children will not equal $this->children
		// also $this->children = $children; is incorrect, becasue $this->children are of type ObjectStorage,
		// but $children - QueryResultInterface
		$children = $this->_childRepository->findByParentUid($this->getLocalizedUid());
		return $children;
	}
}
?>