root ball pic

root ball after shake out

The leaf looks like a grapefruit; but without flowers and fruit, it is soo hard to tell. If you crush a leaf, does it smell like grapefruit?

Some seedlings never bear; and some take such a long time; and almost all seedlings have thorns.

If it is a grapefruit, it probably isn't big enough yet to bear fruit.
It looks like the pot it was in has been restricting growth. If you live where you could plant it in the ground, it would make a big difference.