Divorce settlements are just a number crunching exercise and letting emotions get in the way just hurts the wallet. There is no standard, each case depends on the particular facts so it isn't possible to make comparisons with the outcomes of other settlements. Although the welfare of children is the priority, in particular meeting their need for housing, there are other factors in the s25 Matrimonial Causes Act 1973 checklist of factors that are taken into account.
That means there is no automatic "entitlement" to a higher percentage or indeed to live in a privately owned home. In our case for example although the children lived with me and the assets were split 67:33 in favour of my ex-husband after a long marriage. There are cases where mothers with children have received 25% of the matrimonial assets and in other cases when the value of assets hasn't been that much 100%.
IF your solicitor was in possession of all the relevant facts (value of any assets including pensions and liabilities held in joint and sole names, your respective incomes and ages, the duration of the marriage + any cohabitation before, the number of children, their ages and the number of overnights they spend with each parent) you should be guided by them.
However there is usually a wide spectrum of possible outcomes and 75% may be on the high side so there is room to negotiate and compromise. Conversely your husband may be advised at the lower end. You need to be prepared to revise the position particularly if your solicitor was giving general advice and there is more information comes to light as matters progress.
Starting negotiations from fixed positions isn’t particularly efficient or constructive. As negotiations advance the parties become more and more committed to their positions, continually restating and defending them. The more extreme the opening positions are the longer it will take and the more expensive it will be to reach a settlement. Sadly this adversarial “you v me” approach often results in a mechanical split of assets which leaves both parties dissatisfied.