Navigating in Content Editor is not really what Sitecore Powershell Extension is built for. But it's possible to run javascript from PSE that will do the redirect for you:
$id = $deletedItem.Parent.ID.ToString()
$script = ('window.top.location = "/sitecore/shell/Applications/Content%20Editor?fo=' + $id +'"')
Invoke-JavaScript -Script $script
Be aware that if you add this at the end of your PSE script, it will not show message saying that script execution is completed and will redirect immediately to the parent item.