Custom RSS feed by category

Right now, my RSS feeds are set to send excerpted versions of my posts, and generally speaking, that is what I want.

However, I am managing multiple sites. I’m using a plugin called FeedWordPress in a “child” site to republish articles from a certain category via RSS from the “parent” site. I would like to send the full text of the post for that category ONLY from the parent site to the child.

Is there a way (or a plugin) to make one category feed as full text and all of the rest feed as excerpts?

Thanks in advance!