I can see why you are worried.

How long have you got to go on the IVA? and is there an extra payment due in lieu of property equity? if so how much?
If you just have 13 payments left, then offering half of that - around £5000 in full and final settlement having BEEN OFFERED that by family - not already given it, they may well accept given the job situation.

Alternatively, if its just 13 payments left, with the help offered you are looking like you can manage to scrape through that.
It is important that you keep the IP fully involved, getting the IVA Failed at this stage is the last thing you need, it will reset the stage back to how it was before you started the IVA and swamp you with the original debt plus interest less payments made less IP charges, so we don't want to go there.
SONIC may well have a better idea of how little to offer as a full and final, but I don't think he will suggest more than £5000 so long as there is no property payment due too.

I am concerned that your budget is full of non vital expenditure. I would have thought that after 4 years of an IVA it would look fitter and meaner than it does.
There is lots of expensive life insurance, Lots of money you havn't got going for presents, and a pet that you cannot afford. I would suggest you look at taking a pruning shear to some of these.

Please post back with the payment details of the IVA especially the time and any property equity payment.