I have two small seedling lucuma “twins” that came from one seed, that I just split-up and repotted. These are a year or two old (I didn’t plant the seed, I bought it already growing in the pot), they are about 8 inches tall.
I could see the remnants of the seed’s shell that the two trees were coming from when I detangled and separated them, so I’m sure they were from just the one seed.