I'm not very good at apisto ID but the nijsseni female looks to have a much larger dark blotch, panduro's should have orange tail edge, nijsseni yellow.
What are you feeding? Thawed frozen bloodworms, mosquito larvae etc help mine get in the mood. At 2 inches they should be big enough I think. Are you absolutely possitive you have M + F? I had 2 aggies that the smaller male looked female to avoid getting beaten up by the larger male except once in a while his color would change.