The fry will be the easiest to raise if you can wait about 10 - 12 days after you suspect they have spawned. By then the heads and tails should be popped out or close to it. Once past this stage, you don't need to tumble them. If and when you get her out of the tank, hopefully she will hold, but usually young first timers will spit. If not and she continues to hold, perhaps you can put her in a tank by herself until she release the fry around 21- 28 days after the spawning. If she spits; and the eggs are still eggs, then you will need to tumble them.
There are several different ways to do this and most people end up using their own design. A fast way to make a tumbler, is just put a one liter plastic bottle with the top cut off inside a tank with water and a heater, and fill the bottle with tank water. Add an airline to the bottle. The idea is to gently rotate the eggs, and you do this by adjusting the air. Practice makes perfect, but if you have a fish spit eggs, you have nothing to loose by trying to hatch them out yourself. Once the fry begin to free swim, you can start feeding the freshly hatched baby brine, and algae wafers are good too.