If her name isn't on the deeds, that person below, they should register their right of occupation - go to the Land Registry web site to get the form. Then the husband can't sell the house or mortgage it without notice to the wife.
On the value of services point I accept 4 in 5 women prefer to be with men who earn more than them. It's an important psychological issue for them known as "marrying up". Woemn do it all the time. Men will say they aren't bothered what she earns (as long as she's pretty adn sexy etc) but women look at the job, status, income etc of the man. They may not do it consciously but so many earn less than their man it's a clear pattern. It also makes some men feel good to earn more as well.
On the question of the value of a stay at home parent (male or female) services depends on the marriage. In some marriages the wife does nothing, stays at home but the husband does all the childcare from 6pm, all the up in the nights, all weekends and all housework, rare but I've come across it several times. Other marriages the wife does indeed do everything even when the husband is home so her bought in services might well be £150k of gross income. Even there if the man earns say £750k as in the Macfarlane divorce case, his financial value is higher (or she if it's a woman paying out to their husband in divorce as I did).
I was a bit tongue in cheek. In our marriage we always shared everything but we both had a same view of money, both very careful, never had over draft, credit card debt, happy to buy things second hand etc very very lucky we had the same view. In other marriages the man or woman over spends and if you've got any sense you separate finances to ensure you don't get mired into their financial problems.
A few people are suggesting on this thread that money equals love - that the man who shares all the money or gives the non working wife money is showing love. Interseting materialism for supposedly unmaterialistic non working mothers.
I can't help being post divorce and cynical, having seen so many people before and after divorce, people happy to share everything when married and not so happy when they split up. Give up careers at your peril given the number of marriages breaking up.
Certainly in most marriages both people share money. If you love someone enough you want to die for them, never mind jointly decide how you'll spend the £1m 2006 City bonus. We have moved in English divorce law very quickly recently fro a position that on divorce all the lower earner got was their reasonable needs met to a position where they get 50% even if that is 50% of the £200m he or she earned or inherited or won on the lottery. Most lower earners will think that is a good thing. I think it's morally wrong and treats lower earners as an appendage in a way and does women down and ensures they realise their best investment is keeping a rich man happy, much better than getting good A levels and running Nat West Bank.