489 subsequent entrant visa for new born baby

Hi all I have applied for 489 subsequent entrant visa for my baby on 5/2/2017 and the CO contacted me asking for medical examination and one doucmunets which was missed on 21/2/2017. Thus we have submitted both requested documents by 25/2/2017. From then there is no response from the CO and I m waiting offshore with my baby to move back to Australia. My husband has already left since he has no more leave. Could anyone please tell me how long it would take to grant the visa. I m so depressed since my new born baby and me has to leave away from. Y husband. Please help