Praise be to Allah.
You have hit the nail on the head: your guess is correct. A translation is not like the Mus-haf (Arabic text of the Quraan) and the same rules do not apply. A translation is like a tafseer (commentary), and so a menstruating woman is allowed to touch it. Your analysis of this matter demonstrates astute reasoning and excellent thinking skills, which makes us feel that you will soon embrace Islam; may Allaah guide you to all good.