We're right in the middle of sorting this and am having to tread very carefully.
I have one DD from my prev marriage and 2 DSS from husbands prev marriage. No DCs together
Only DD(17) lives with us, boys (18 and 20) with their mum but of course we see boys often.
Most of equity in our house is mine from before I met DH. If we divide our house equally between all three, my DD loses out as her inheritance is diluted, plus DSSs will inherit half a house each from their mum AND a chunk of this one. ExH is waste of space so no inheritance coming to my DD from there.
Was dreading the conversation with DH, but put it like this: all of them should end up with a similar inheritance as they are all equally loved. He was happy with that so I suggested this: We roughly value the boys' mums house and work out what half of that will be ie what they will get each.
Then we divide up our house. My husband has the right to live in our home for the rest of his life or if I outlive him,I have the same right, thats important. The equity of our home though will be put in trust for all three of them, with my daughter getting extra, equivalent to the amount each boy will be getting from their mum. That way they all end up with exactly the same amount, but my DD ends up with more of mine.
Hope that makes some sort of sense.
In terms of inheritance from grandparents, what I inherit from my mum will go to my DD on my death, what my husband inherits from his parents goes to his boys on his death. Unless we have jointly spent it before then.
Dunno if that makes any sort of sense?