Extenuating Circumstances?

If you don't have documentation or someone who can act as an independent witness it will be difficult to prove

You should put it down - and then when they bring it up explain what happened and hopefully they will believe you

I feel for you with regards to the UCAS points as I have a similar situation although my extenuating circumstances are very different to yours but cannot be proved.

You can prove your mothers death with a death certificate... which is harsh as I am sure you don't want to recall it but is the only way. The rest would be up to them believing you although dealing with death at 16 - I think most people would sympathise that career focus wasn't exactly priority on your list. Looking after your brother can only be confirmed by your brother and possibly his school....And looking after a child when you are still pretty much a child is quite a weight to take. As with the other stuff you mentioned, I would say something like "very personal family related problems with my father and step-mother which severely affected my ability to study on my first attempt however due to my commitment to my career, I believe my second set of results are an accurate description of my performance and my university degree score helps prove this point." (I'm assuming you have a 2:1/1st here or are on your way there.)

Sorry to hear what you've been through and I hope you do find the job you are looking for.

Sorry to hear this, it doesn't sound like your life has been easy over the past few years. You are definitely entitled to claim extentuating circumstances as all of this has been out of your control.

What I would do in your situation is:
Go to http://www.gro.gov.uk/gro/content/certificates/

Order a copy of your mother's death certificate. Also order your own birth certificate as this should have your mother's name on it, proving that you are related.

Also, order a copy of your father's new marriage certificate for the person he remarried to.

When you apply, show that the loss of your mother obviously affected you, and show them the evidence to back up the fact that this event happened, in other words, her death certificate.
Also show them your birth certificate to show that you are related to her.

Also explain that during this time of emotional hardship you had a lot of issues to deal with, such as taking care of your borther and also adjusting to the fact that your father got remarried.
Then show them the marriage certificate.

Then explain that the low UCAS points you got at first sitting were a result of this situation, and that they don't really reflect your normal academic performance.

Also, before you send off your app to any company, call up Graduate Recruitment and explain the whole situation to them over the phone.
If you can, get the person who you spoke to to process your application when it comes through, since they are already aware of the case.

You definitely have extenuating circumstances, I know people who have got ext. circumstances for less traumatic reasons.

Good luck