Yahrzeit dates

FoR: Conservative Jew with little knowledge

I think I have the Hebrew date correct for a Yahrzeit ( I looked it up but I’m not sure of the time of death yet) but I’ve always been connected to the Gregorian date since it’s what I could remember as a child (I lost her while very young). She is Jewish but I don’t know her level of practicing,or anything should I just use the date I’ve always known or maybe do both the Hebrew and Gregorian? I’d love some opinions, this my first year doing Yahrzeit so I’m just trying to learn what’s best to do, ideas, or even tips on what I am supposed to do.

Idk if this context is needed or not but it’s my mother, the giver of my Jewishness that has brought me here 💙