Yes! To see the availability of other LibraryH3lp users or queues, you'll want to buddy them (if you haven't already) - just as you would most any other IM account.
You can manually add a new Buddy in the webclient for staffing by using the grey circle with a plus (+) sign at the top of the Guests & Contacts list. If you are using a third party IM client, it probably supports adding a buddy/contact. The Jabber ID for a user will look like firstname.lastname@example.org and email@example.com for a queue. (If you are using a regional server instead of the main US server, you'll have to adjust the domain slightly to match your regional server. E.g. firstname.lastname@example.org and email@example.com for the Canada regional).
But manual buddying gets tedious. To simplify the buddying process, your top-level admin user can opt to use the "Manage Contacts" capability within the users management page (US, CA, EU, SG). Details on how to use the Manage Contacts feature.