Advice needed re divorce settlement

[DottyRotty]

Sorry if this is long but I really need some advice regarding my brothers divorce.
So Sil has left and divorcing DB.
Children all grown up.
Sil has been working self employed but not declaring to the tax man.
Sil states that she earns £100 pw. More like £400 pw. (Not sure if this is relevant).
Sil and her sister are on the deeds to their mothers house.
There is a deed of trust in place stating that they will only benefit from house when the mother dies.(she is 80 & showing signs of dementia).
They are planning on selling the mothers property and all moving in together in a larger house. (Not sure of exact details)
The profit from sale of DB house is around £140k.
He also has quite a good pension.
Sil is claiming that as a 'low earner' she wants 65% of the property & 50% of pension.
DB is unlikely to get another mortgage & will probably have to rent.
Is he allowed to use her interest in the mothers property in a divorce settlement?
Especially as she will have use of this money now?
Also, as she is buying another property but he will have to rent is she entitled to 65% or should he fight this?
I am really worried as he is mentally in a very bad place (did not want divorce ).
Also his solicitor is on good terms with her solicitor.

His solicitor really doesn't seem to be fighting his corner and just advising him if it goes to court will cost him more money in the long term.
I don't want him to make a mistake by not fighting this and regretting it later on.
Anu advice would be greatly appreciated.

Don't read anything into the lawyers being friendly. It's very common. It's a small world. It doesn't mean he/she won't fight your brother's corner professionally.

The mother isn't dead but the house has been put into SIL and her sisters name.
She is going to benefit from the mums property as they are poolin their money and buying a large 6 bed house.
He is not a high earner and looks like he will be left renting a 1 bed flat.
Obviously his rent will go up in the coming years and she will have her own property going up in value.
Just seems so unfair

Thanks eurochick that is reassuring.

Any other advice please?

The thing is that the difference between giving her 50% of £140k and 65% of £140K is £21,000.

Then there is the dispute over what she is earning as a self employed person (but not declaring income) which is very difficult to prove.

Quite often when there is disputed financial circumstances the costs of the solicitors can start mounting up quite quickly and therefore sometimes this will eat significantly into what he would save.

If he has a lawyer already then he should be able to give an idea as to what a contested financial proceedings route would cost.

As someone else said most lawyers in a town all know each other as it is a small world; they will still fight their case though!

Thanks All
I think the problem is that sil is stating what she wants and he is being told that there is no point in fighting it.
Surely if there are no children involved then a 50/50 split is fair?
She has been into the property & removed items and damaged his things.
He changed the locks as she was not supposed to enter the property without prior notice.
His solicitor has told him he must give her a key.
It's just such a mess and I just want him to get a fair outcome.
As I said he is not a high earner and she has more chance of moving forward than he ever will