WPML lets you create one set of forms with Gravity Forms, in the original language. Then, you only need to translate the texts that appear in these forms to other languages in your site. WPML will automatically display the form in the correct language. Since the same form is used for all languages, any changes you apply to it will instantly be visible in all languages.
Getting started and what to check
Make sure that the following plugins are activated:
WPML Multilingual CMS 3.2.6 (or higher including String Translation and Translation Management add-ons)
GravityForms 1.9 (or higher)
GravityForms Multilingual 1.3.3 (or higher)
If you are a site owner working with a developer, you can ask them to make sure the above plugins are installed and set up.