In DiscountDuck, all the widgets displayed in your store can be fully translated.
To translate the widgets, go to the configuration page and select the widget you want to translate ( Quantity breaks widget or cart widget ).
Change the translates
The quantity breaks configuration is grouped by section, all the translates you can changes are present in the sections.
Just change the text in the input the modify the translate.
click on "Save settings" to validate the changes.