Using "may her memory be a blessing" as a goy writing to a Jewish relative

Edit: this has been solved now, thanks for y’all’s help!

I (agnostic raised by Christian parents) am writing to my uncle (Hasidic raised by even more devoutly Christian parents) in the midst of a crisis he’s dealing with, and mentioning my grandmother/his mother (Southern Baptist for most of her life, never Jewish), who passed away a few years ago. Would using “may her memory be a blessing” be appropriate in reference to her?