Financial split 50-50

Hi,

I am splitting from my wife after 6 years of marriage. We have a 16-year old stepdaughter and 2 6-year old twins. the twins will live with me going forward. We now live at separate addresses - myself in my parents' spare room with the younger 2 children, and my wife in the former marital home. I am currently still paying for the mortgage on the marital home. The younger children go to my wife most weekends, so they spend about 6 nights per month with her. My wife doesn't work.

My wife has not worked during the 10-year relationship. The relationship can be summarised as:
* 3 years, I supported my wife and stepdaughter financially. She didn't work.
* 4 years, my wife was pregnant/ a SAHM
* 2 years: younger children went to school, but my wife still didn't work. The last 6 months we have been separated and I have still been supporting my wife financially, while having the younger children living with me.

Throughout the relationship I have been the sole breadwinner and financially supported both my wife and stepdaughter. I brought in assets from prior to the marriage and these were used to buy the marital home.

I know that homemaking contributions are taken into account as equal to breadwinner, but on the face of a marriage of such unequal contributions, will I still have to give her 50% of assets? For example, before having children together, there were 3 years of total financial dependence on me. For me it seems grossly unfair if I have to give my wife 50% of my net worth, about half of which predates meeting her. Would a departure from 50-50 be considered under the circumstances?

My wife has no qualifications and I'm quite highly qualified so can earn a fair amount more than her.

Thank you!