AppleScript: How to create a new Finder window for a folder that is already open?
Simple way to make a New Finder Window to the Desktop.
set myTarget to ((path to desktop) as text)
tell application "Finder" to make new Finder window to folder myTarget
From https://macscripter.net/viewtopic.php?id=36300
I think this code does what you want.
Code:
set targetFolder to POSIX file "/Users/Me/Desktop/MyFolder"
tell application "Finder"
set finderFolder to item targetFolder
set lstTargets to target of every Finder window
if {finderFolder} is in lstTargets then
set target of (make new Finder window) to targetFolder
end if
end tell