Australian here.
To all those saying OP can't get a visa, she absolutely can.
The rules here are that applicant has to have the majority of their children living in Australia, pay an application fee of nearly $50k and be aware there's a significant wait time as there are many applicants.
So it's entirely possible that OP could get a visa.
As to your actual question, OP, you are not being unreasonable to want to come to Australia, particularly if children have indicated they'd be happy for you to move here.
Regarding your husband, if he doesn't want to go that's his prerogative, but obviously you have to decide what is going to happen with your marriage.
The other option is to come out for long stays and see how it all goes before applying for a visa.
And to the poster/s saying Australia is misogynistic and racist, for goodness' sake get a grip. Misogyny and racism is everywhere. Your country's hardly a beacon of righteousness and fairness for all. However, both countries have a lot to offer and nowhere is perfect.
Good luck with it OP. Australia has much to offer as many new residents from the UK and all over the world already know. 😀