If a temporary migrant has a baby with an Australian, the baby is a citizen. But if the couple splits up, the foreign parent doesn't have the right to stay in Australia and stay close to their child. It's often up to the Immigration Minister to decide whether or not it is in the public interest to grant the foreign parent a permanent visa.
Getting the Minister's attention is a tortuous process. If the Minister refuses to grant a visa, then there may be no choice but for the foreign parent to leave the country, which means either a painful separation or taking the child away from the Australian parent.
The rise in temporary migration to Australia means the number of such cases is only likely to increase.