my guess is that you don't need a smaller female, just a bigger tank. whenever my females were stressed/frightened their color would fade and the horizontal bars would be displayed. being in a 2 gallon tank with nowhere to hide from an over-eager male is probably stressing her out.
In a larger tank (I used a 20 long), stick a couple of plastic plants in for the female to hide behind. I used to suction cup some to the side of the aquarium for the female to hang behind at the surface. even when the female is ready to breed, she'll continually seek places to hide...the male will then approach her and do his little dance to coax her under the nest. Once she's comfortable spawning may take place.
Also, think about adding the Blackwater Extract...not sure why it works. Maybe the light tea-like color of the water cuts the light and creates a mood? It worked for me.