I was a skimpy for almost two years, worked all over southern WA and then was based in Kalgoorlie, but that was way back before DD.
Roary is right, the girls are everywhere, if that bothers you about DH being fi/fo, and the culture is that of hard work and hard drinking.
It's very um bogan!
There is, or was money to be made, but lots of relationships don't stand it, and those with sense do it as single men, make the money and leave to get married/have a family.
Saying that, Kal has OK (relatively speaking) areas, and some nice restaurants, but it's so isolated.
Smaller towns have nothing but the minesite, pub(s) maybe a shop and a roadhouse and some are just really weird (Collie anyone?!).
If the money is really good, and your kids are really young, I'd at a push consider Kal for a few years, depending on what it's like now. My experience is of 12 years ago but as soon as the kids are school age I'd go back to Perth.
I got pg in Kal, and said to exdp that I'd stay for 5 more years, because then, the rents were cheap, he had a good job, I could have gone back to work, we had great friends and would have needed minimal childcare, as he worked 6am-6pm and I did 3-5pm till 10-12, I could also take time off whenever I wanted, and could do a 3 day week, right up to 7 days depending what I wanted.
5 years was my limit though, as I didn't want my child to go to school there.
We came back to the UK anyway and baby was born here.