Mother, aged 83 dies in UK. In her Will she leaves her entire estate
between her two daughters (aged 52 and 55 years).  Mother had
re-married nine years previous (he now 84 years). Latest Will made
after second marriage.  Will states she leaves nothing to her (second)
spouse because he has adequate funds himself - he owns a house (where
mother lived).  Mother leaves company shares and two accounts with
around £136,000 total.  Her property home was put in daughters' names
15 years previously when first husband died and sold six years prior
to her death.  Plus jewellery that was gifted to  daughters before her
death. A Trust Fund set up over seven years prior to death in names of
mother and two daughters (now valued at around £120,000).  The mother
earned £4,000 per annum from Trust(total £28,000). Should this form
part of estate now?  All estate the mother had was from her first
husband (45 years married) - the father of her daughters.  The second
husband has now made a claim on her estate under the Inheritance
(Provision for Family and Dependants) Act 1975.  During their marriage
they had separate bank accounts and his house is in his name only. 
The mother contributed towards the upkeep of the house and living
expenses only.  The second husband (a widower when they married) has
two sons who stand to inherit his entire estate (house, valued at
around £150,000 to £170,000).  Not know what bank accounts he enjoys. 
What amount can the second husband expect to be granted from the
mother's estate?  He suffers from angina and both his parents died in
their 60's.

Please take a look at:

http://answers.google.com/answers/threadview?id=351037

And in particular:

"The Inheritance (Provision for Family and Dependants) Act 1975

If your partner dies intestate or his/her Will fails to make any or
adequate provision for you, you may be able to bring a claim under the
above Act for reasonable financial provision but you have to have been
living together for at least 2 years before death and be dependent
upon the deceased. The 1975 Act is no substitute for a properly drawn
and regularly updated Will. Proceedings under the Act are inevitably
expensive, protracted and stressful whereas the cost of making a Will
is by comparison inexpensive. Remember that marriage will
automatically invalidate an earlier Will unless that Will was written
specifically in anticipation of the marriage."

http://www.ts-p.co.uk/information_sheets/Cohabitees%20Your%20Rights.pdf

According to this, the surviving spouse has had to have been
'dependent upon the deceased'.

As your Mother's husband 'had adequate funds himself', he may not be
entitled to any more but who knows what his financial situation is
today?

It is possible that the Trust Fund will fall outside of your Mother's Estate.

Are you and your sister the Executors?

Whatever, you certainly need professional advice and it will be far
better if you can come to an amicable settlement with your stepfather,
rather than to pursue litigation.

I would suggest that a good starting point would be for the Executors
to investigate how much, if any, the Deceased contributed to her
Husband's upkeep.

Get her bank statements over the last 3 years or so. If these are not
available order copies. From these (and her cheque books) it should be
possible to determine how she was disposing of her income.

Even if, in all fairness, her Husband was dependant upon her to some
extent then at his age and with a health condition, it should be
possible to buy an Annuity to cover whatever contribution is
indicated.