So light translates an adverbial expression meaning “from lightheartedness.” Because harlotry was so light to her is translated a variety of ways: “So shameless was her whoring” (Jerusalem Bible); “Because Israel’s immorality mattered so little to her” (New International Version, but Judah should be in view here); and “Through her shameless prostitution” (Die Bibel im heutigen Deutsch). Another possibility is “Because being a prostitute didn’t bother her.”
She polluted the land (so most translations) represents one possible way of reading the consonants of the Hebrew text. However, Hebrew Old Testament Text Project prefers the Masoretic form of the text, that is, the text with vowels that has come down to us. This text may be rendered “she defiled herself together with the land.” The Septuagint omits this statement. Those translators who choose to follow the Revised Standard Version text, polluted the land, should refer to the discussion at verse 1. If they follow the Masoretic Text, then they may say something like “she made both herself and the land unfit for God [or, for worshiping God].”
Committing adultery with stone and tree means “she committed adultery by worshiping stones and trees” (see 2.27).
Quoted with permission from Newman, Barclay M. and Stine, Philip C. A Handbook on Jeremiah. (UBS Helps for Translators). New York: UBS, 2003. For this and other handbooks for translators see here .