The only thing I can tell you for sure is that your avocado seedling is definitely half something other than Hass. This has nothing to do with what it looks like because I don't think it's possible to identify the parentage of your seedling from the leaves. Leaf morphology is highly variable, especially when comparing very young plants with mature ones.

Rather I know Hass could only have been one parent because avocados require cross-pollination with another variety that has a different flowering habit (These are grouped into A or B varieties based on what time of day the male and female flower parts are viable). Below is a short list of common varieties that would pollinate type A flowered Hass.

But it seems a bit arbitrary to know the parentage anyway, since you're dealing with a seedling that by definition is genetically distinct from both it's parents.

TYPE B FLOWER AVOCADOS:
Fuerte
Jim
Kahaluu
Murashige
Nabal
Sharwil
Stewart
Whitsell
Zutano

fabaceae_native,

Thanks for your explanation, I'll check the varieties you mentioned for the leaf shapes. In the worst case, I have a new variety ! :)
I like how it looks and grows, very bright green and compact.
I just replanted it in a 5-1-1 mix.

And, it will take anywhere from 5 to 13+ years for it to bear fruit, so be patient :-)

Patty S.