You can try adding a footer widget:
Go to Graphene Options, click on the Display tab, and scroll down to the Footer Widget Display Options. Set it to display at least 1 widget.
Next, go to your widgets section, and you should have a Footer Widget Area in which you can place any of your normal widgets. They will appear under your comments section.
If that doesn’t give you where you want, go to the advanced tab, and play around with the various Action Hook Widget Areas. Keep track of what you’re doing or you’ll end up with a mess…
Hope this helps somewhat,
Richard 🙂