I downloaded a few IRS forms, filled them out and saved them. Then I noticed in the upper right hand corner, there was the name Mary where the Sign In is located. I clicked on Mary, and it gave me the option to sign out. I signed out, but it made me wonder what that means.
Was someone signed in on my form? Is there any reason to believe that my information is compromised?
I don't think so. What you saw is most likely the Adobe account used in the application itself, which has nothing to do with the data you entered into the form. If you post a screenshot of what you saw we could say for sure, though.
What that means is that someone called Mary logged in - not to the form - but to the computer itself, to use Adobe software, sometime in the past. If you have any paid subscriptions, check them, in case you gifted them to Mary!