What is the data, and what is a specific users ‘page’?
DATA
Data consists of essentially a home visit checklist.
examples:
is the home clean? yes or no
is the backyard fenced in? yes or no
how many people live at the home? (enter in a number)
additional notes (text box)
PAGE
Page consists of a profile page of an existing dog or cat with pre-populated data already on it. The data from the home visit will append to the profile page in a new section. This data will not be visible by front end traffic to the site. Only visible on profile pages to logged in administrators.
Is someone being allowed to update another user’s profile?
In the scneario described above, yes. Volunteer submitted data will add to the existing dog or cat profile page.
It sounds like you want to use Gravity Forms to update an existing post (or page.) Controlling access to the page (“This data will not be visible by front end traffic to the site. Only visible on profile pages to logged in administrators”) is not a function of Gravity Forms, but of WordPress or a WordPress plugin like Members. That would be used to limit access to the content to logged in administrators (that would need to happen with or without Gravity Forms.)
As for updating an existing post (“pre-populated with data already on it”), are you going to be editing or changing information on that dog or cat profile page, or just adding to it? There is probably a way to update an existing post to add information to it, but updating information already in the post will require more work.