My layers don't show up

[Carolina McGarity]

Hello, 

I am a student working on a World Map class project. I created two layers in our collaborative map, however neither I nor anyone else in our class is able to see them. I can go and see my work in the "Revisions" history, or as separate layers in my profile. However, I cannot add the layers in my profile to our map; it just gives me a "New Map" option. My professor who created the map gave everyone permission to edit, and I have given everyone permission to edit mine. 

Does anyone have any idea how I could get my layers back on our group map? Let me know!

Thank you!

Carolina