<human>: Hey there,

The title sums up the situation. We ended our relationship on good terms and on the agreement that it was a "no contact" breakup. She wanted to pursue her career in a remote area of the country and did not want to move in with me, so we agreed to break it off cleanly. 

I found out that her sister had a very serious form of cancer about 6 months ago, and I contacted her sister through email to offer my good wishes in her treatments. 

Turns out that the treatments didn't go as planned, and my ex contacted me by SMS that she's terrified of her sister dying. We were exchanging texts yesterday, all on the topic of her sister with me offering support. 

I am currently in a very serious relationship, living with my girlfriend. My current girlfriend is very supportive and has no qualms with me helping out my ex.

The issue is: while I care deeply about the well-being of her sister, it's a very odd situation that my ex has put me in, as I'm not really a part of her life anymore. I feel that she should be using her support network of family and friends, not exes, but I'm also not one to turn my back on someone who needs support. What's your take on it?

Can you succinctly summarize the text in 1-3 sentences?
<bot>: ex messages me after 1.5yrs to ask for support with her dying sister, I don't know how to help her or why she's contacting me specifically.