Is there an option to add pronoun preferences to the constituent's profile?

Yes. You can add this feature by turning on “non-binary” as a picklist option for gender under your Account Settings. Mouse over your Organization’s name in the upper right corner of the software and click on Account. Once on your Account Settings select the “Options” tab and look for the Show Non-Binary in Gender Dropdown? toggle setting under the General section. Turning this setting to “Yes” and saving the page will update the Gender field to include “non-binary”.

Turning this setting on will also add the Pronouns field onto the Constituent profile. The Pronouns field will have an editable picklist so you can customize the values you wish to make available for selection.