You both were struggling at the same time, and while she always took the initiative to reach out to you first and see how you were doing all while carrying the pain of losing her child - you couldn’t do the same once in a while? Sent her a quick text, or a quick phone call to make sure she knew you were there for her?

At the same time, I understand that you had your own demons to deal with. I do believe you could have communicated with her at some point and let her know you needed time though. At this point, communication is key (always will be in any situation). Sit her down and talk to her.

Overall, shit happens.