If she is a big part of your life (sounds like she is) I don't see anything wrong with asking your T on how you can best help her. On the same note, I think most T's would be willing to at least point you in the right direction in terms of resources...

My personal experience: My friend's MIL commited sui and my friend was struggling and it was hard for me to see her struggle. I brought it up in a session and my T gave me paperwork, suggestions, online links, etc. We did not spend the whole session on that topic. He basically gave me the tools/direction to do the research and find the information I was looking for. AND, he thought it was good for me to be looking for help in supporting her because he knew I did not have the coping skills to address on my own.

just my thoughts.....