Not necessary i had a pair of neolamprologus multifasciatus spawn at an inch and i was like wow that was small i think she had like 2 fry.
As for flowerhorns yeah your right not normal for that size but flowerhorns are not normal fish the thing is when fish are bred with others to make hybrids no one is sure what will take place and even more so is that most hobbyist are not sure they will be able to produce, most hybrids are sterile..
But its not unheard of fish breeding at one month of age..
Ya it just shocked me they are so young and if i was to estimate i would guess 100+ fry but ill see how many will live. They are in the tank alone. Are you experianced with flowerhorn fry? What should i feed them ?ETC.....

although no my exact fish mine looks identical. Do the dark black lines mean anything. Because all the others i have seen dont have the stripes?