How small are they, exactly? Most fish wont reach maturity until they are about 3-4 inches. My baby shubunkins have started showing tubercules at about that size.
It depends on how long it will take for them to lay the eggs. As soon as the temperature begins to rise that will trigger her to begin producing more eggs. You can condition the pair by feeding high protein foods and doing very large water changes. Usually a large water change can trigger them to spawn if they are close.
Dont put her in a breeder net as she needs the male to bump her and nudge her to stimulate her to release the eggs. Once she does this, you can remove the eggs (I put tons of plastic plants in my tank and them just removed those since the eggs were all over) to a breeder tank. I just used a 10 gallon with a heater and a sponge filter.
I made my own sponge filter with an Aquaclear sponge, an airpump and some tubing. Good luck!