Hi Amy,
At this time, this isn't something anyone is working on. You are welcome to submit a ticket to request it (to
https://github.com/DSpace/dspace-angular/issues), but we'd have to locate a volunteer interested in adding/creating that link.
For now, the behavior is similar to what you have noted. The expectation is the user can go to "New -> Item". This pops up a Collection selector. However, if you are already on a Collection homepage, then the *current Collection* will be listed at the top of that Collection selector (making it easier to quickly select the current Collection).
Tim