Your results indicate that both parents carry the same albino mutation. There are many different genes that can mutate to produce non-green leaves. It is not impossible for particular plants to carry two or three different albino mutations. The expected number of green to albino seedlings if both parents carry the same two albino mutations would be 9:7 That would explain your results.
However, the luck of the draw always operates. Under typical circumstances albino seedlings appear when both parents carry the same albino mutation. We then expect that approximately 25% of the seedlings from the cross will be albinos. That holds reasonably well when we produce many seedlings. So if we produce 100 seedlings from the cross we expect that approximately 25 would be albino. However if we produce say only eight seedlings then we would be very lucky if two (the expected number) were albino. The luck of the draw indicates we could get a different number.
Three albinos out of five seedlings when we expect there to be 1 1/4 albino seedlings (only one albino mutation involved) will happen by chance ("the luck of the draw") about one in 10 times. That would suggest that it was just chance. You might want to try the cross again with many more seeds (after all you only need to germinate them to check the leaf colour).