DH earns about $1100 a fortnight and i don't work so we end up getting about $580 a fortnight for the two kids, that includes rent assistance, Family Tax benefit, and a small amount of Parenting payment.
Everyone gets baby bonus when baby is born which is currently $4000 and was set to go up to $5000 in July but of course we've just had a change of government so we'll have to see if that changes or not.
You also get $600 for each child with your tax return at tax time (once again we'll see if that changes with the government or not)
From what i understand in order for Family Tax Benefit to really be affected in any huge way you'd need to be earning a total combined income of like $50-60k a year