New to ..not shure about temp nestbox/eggs

[signaltonoiseau]

Hi Guys & Girls
I live in Melborne Australia
I have had a pair of white ringnecks for 18mths now,they were 2yrs old when i got them.
Ive had a bad car crash and cant get around much and my birds have been good company..
I havnt handled them but they dont go bananas when i go in there cage now.
last year. They were having s.. but no eggs.
this year.August 1st they started again..
There is 4 eggs in there nest box.
I estimate approx 2wks+ the hen has been sitting on them..only coming out for 1min for food a few times a day
The male now is spending large amounts of time in the box also...
I watched female and male eat more Cuttlefish bone recently.they have my garden fresh seeding grass,dandelions,thistles,corn,apple,carrots,celery,lettuce,chillies,potatoe and good quality seeds with vits..
they get vits with there water too. so hopefully they getting good food

Im a little worried about the temp...its cold down here in Melb even tho its supposed to be spring.
droppin to 6/7/8c during the night...
Id like a little help
do i need to keep the room they are in at a certain temp or not let it drop below a certain temp??????