Oh dear ....
I've been peripherally involved in a couple of cases re wills, and your exH is not doing the right thing AT ALL.
you really need to get it sorted out now, and in your daughters' interests. They're his daughters too, and he should be providing for them in his will. It is quite appalling frankly, that he isn't.
There's a famous fictional example here -the start of Jane Austen's Sense and Sensibiliity. Read that and weep ...
Basically there are two things to consider
-
your DDs are his dependants (yours too, obviously, but it's his estate were talking about).
-
AFAIK, neither you nor your daughters would be permitted by law to contest his current wife's will.
So, worse case scenario -- your ex leaves a substantial estate to his current wife. She remarries, or dies intestate. By law, your will is voided when you marry and your spouse is assumed to be your major heir. So the SM could leave all "her" estate to whomever she pleased, and neither you nor your daughters could do a thing.
I saw this happen to a family friend. Her parents divorced. Her father remarried, and they didn't think about his will. He was pretty well off so it was a reasonable estate. He died and left everything to his 2nd wife. Again his children didn't do anything they didn't realise they should have. She died and lo and behold! In her will, envy thing had been left to her children (there were no children of the 2nd marriage). So her children got the substantial estate of my friend's father, and my friend and her brother got absolutely nothing. They had no grounds on which to contest the 2nd wife's will. They found out too late-- that they should have contested their father's will. They were likely to have been awarded half the estate between them.
Now, if there's not much to leave, well maybe it's no big deal. If its just his interest in a house shared with his second wife. But your daughters would be considered by the law (as I understand it) to be their father's dependents, and so should be provided for clearly, and fairly.
I'm talking purely about the money above, but don't underestimate the emotional impact on your daughters. My mother was left out of h father's will, because she married very well (in my father's family it's all trusts and big estates) and he thught she didn't need anything from him. But she was devastated. Luckily my aunts are all wonderful sisters and split the estate 4 ways. But whenever I think of doing something other than that which is absolutely fair with my will, in relation to heirs etc, I think if seeing my mothers face on hearing about her father's will.
IMO, "fair" in this case would be at least half your exH's estate to his daughters, if not more. Alternatively all his estate in a trust, which his current wife administs and has the use of the income for herself, but the capital eventually goes to his daughters (that's the arrangement I'm familiar with). But young children, starting out in life, need it more than an adult frankly.