Suppose you hadn't told her.... Suppose you barely spoke to her in her last few months because you were afraid she'd know, afraid you'd have to explain why you were trying to R or considering D or whatever...
You might feel guilty then too.
Truth is, you didn't cause it, and for crying out loud, if her doctor could't prevent I'm guessing you couldn't either.
Maybe what you're feeling is a slight delay tactic of your psyche before dealing with it all fully. That's ok too.
I'm so sorry you lost your mom. I lost my dad 3 weeks after dday2. It is extremely difficult.
I am so sorry for your loss. Be kind to yourself and go through the grief... I think the biggest blessings are the hardest to get over losing.
Let go of the guilt, you are not so powerful to have either caused or prevented this.
Peace and prayers for you and your family.BW - Reconciling
edited for typos (I always have to!)