She should ideally be two years before being bred and most breeders also own the male. Be prepared to spend A LOT on raising babies, money you won't be making back unless you raise hundreds of high end morphs.
You will need multiple cages with all the proper lighting, a reptile vet in case mom or babies get sick or egg bound. A endless supply of small feeders, roaches work best for this as they breed quickly. A back up plan for any babies that don't sell, a plan on how to handle deformed babies.
One female dragon can potentially lay 75+ eggs in one season, thats a lot of food and cages. If your mom is interested in breeding for profit, its really not a good idea.
You need to also consider the toll it takes on the female and whether you want to risk her health.