Yes, you can add an assistant to a management organization chart in Lexchart.
Step 1. Add the assistant card and link
Step 2. Switch to manual mode
Manual mode gives you control of the position of all cards and links.
Step 3. [Optional] Create space between the manager
This step is just personal preference to create vertical space for the assistant. Depending on the layout of the chart, this might not be necessary.
Step 4. Select and move the assistant
Step 5. Select and move the line
Now you have moved the assistant to a side position above the rest of the org chart.