Hey Claire,
It is possible to copy the attributes and location, just the attributes, or just the location of a feature when editing in Collector. To do this, select the feature you're interested in copying and choose the context menu for that feature (in Android the gray arrow in the bottom-right corner). In the context menu, the option to Copy will let you choose from the three choices I listed above. This will work with the same feature layer, but will give you the ability to create coincident features.
-Scott
