I finally mailed a note to my mother advising her that Lulu was gone. It's been almost 2 weeks... I can already predict the response that I'll get from her. She'll have a very distant response saying something along the lines that Lulu was a great cat and companion and offered lots of love and she'll be missed.
The response I got when Sassy died - it could have been the same if I had said my car had been totaled. She's just totally unable to make any sort of genuine emotional connection...