Webinar Setup - External Account User?

I am a Zoom Webinars Plus user (formerly Zoom Sessions).  I have a colleague from another organization (with their own account) who is setting up a Zoom Webinar (not plus) that my members are also invited to attend.  Is there a way for her to be able to add me as an alternative host only her webinar?  I wanted to help her with some of the branding details etc.  I don’t need/want access to their Zoom account administration.