OP I have spent some time investigating career change as well. I think it is important to step back from your current dissatisfaction and work out what your issues are in your current career and whether or not this will possibly be transferred to your new occupation.
Will any change impact your family time so negatively it will make you unhappy.
How will the financial changes impact your and DH's need to work more hours, are you happy/able to support this?
Will you be able to complete you family plans?
Have you flexibility to return to your current work place/occupation if you choose?
What entitlements will you give up/gain that may be of benefit?

I guess really it is a pros and cons list. I decided against change when I realised I would have to work fulltime at least initially and the ground work would severely eat into our family time with me studying etc. It sounds like a cop out but I didn't want to do that at the age and stages my kids are and the way DH and I are with the little support we have from others. I am lucky enough that I also have heaps of sick leave/holidays/LSL that I would be leaving and this was a big indicator for me too. The main thing was I was unhappy with the way PT staff are treated and a lot of the politics of my workplace - not the actual job. So as a result I have made a big change in the way I deal with it all. I also have tried to find other challenges in the workplace in terms of learning some new skills and in the way I deal with my colleagues.
Good luck - I hope you find some alternatives!