She obviously considers herself a Jewish mother even though the Orthodox rabbis disagree. She’s been observing Jewish customs to a greater or lesser degree since at least 2006.
At some point she is going to want to do something that is going to require her to convert like becoming a citizen or Israel or wanting to be recognized as a kosher-certified Jew in the Orthodox community. She may then decide to convert.
Becoming a Jew seems to be somewhat more getting citizenship in an Indian tribe than in becoming the member of a religious body. It would seem that being the grandaughter of a Jewish woman should have some weight.