DD3 has left the idiot - what now - advice appreciated!

Most of you will know about DD3 and her Idiot (or husband!). They have decided to call it a day and she has moved back in here, which we are happy with in the short term. They are in the process of clearing the house and I think we are going to rent a storage unit to put her furniture in.

He has offered her what we consider to be a paltry sum (less than half the rental they are paying on their current house) considering what he and she earned as directors of his company. She will cease to be a director so his income (assuming things stay the same) will effectively double. He is going to pay the tax, insurance and remaining lease on her car (It was a Christmas present so the lease ends in December)

She is accepting more or less what he offers and is keen not to make a fuss to maintain 'good' relations with him for the children (he said he would have the children for a couple of hours yesterday but didn't as he'd been to a stag night and felt ill!!!!)

She has agreed to go to the CAB for advice and DH is thinking of going to see a solicitor so we have some knowledge.

Can anyone offer any insight into what is reasonable for her to expect and what benefits etc she might get. She is reluctant to go to the CSA.

I'd like him to pay very dearly for the distress he is causing DD and two of my DGC and, therefore, the distress, mess and hurting eardrums that DH and I are suffering. I realise that is not quantifiable and we will all be fine in the long run but my blood boils when I consider him with just the blinking cat to look after.

Sorry for this long post but we are in the dark about this sort of thing and you were all so supportive last time I asked for help regarding the idiot!!