DH and I are looking to get wills written - we should've done it ages ago but kept forgetting 
We are thinking of getting mirror wills (i.e. when one of us dies, the other inherits the whole estate) but are struggling with what to do about our children.
DH has a son from a previous relationship and we have a daughter together. DH is planning to split his estate 50:50 between DSS and DD, whereas I'm not sure what to do. I certainly don't want to leave DSS out of my will but I am aware that he also has his mum's side of the family to inherit from whereas DD will inherit solely from DH and I.
I was thinking maybe an 80:20 split of my estate between DD and DSS? So overall that'd mean that DD got 65% of our combined estate and DSS would get 35%.
However DH is a little hesitant about this because he's always tried to treat DSS and DD equally and he's worried that because we both work, have savings and own property, that DD will be much better off than DSS whose mum and stepdad are not in work and therefore unable to save etc so DSS won't inherit much from them.
My argument to DH is that if one of us ends up needing care then that could wipe out all of our inheritance anyway so how much it's looking likely to be may be irrelevant, and that although I don't want to leave DSS out of my will, I just don't feel like it's fair on DD if her mum's estate is shared but his mum's isn't...?
Not sure if all that makes sense and I hate even thinking about things like this. I realise that it's my estate and I can do what I want with it but it's so hard to find an agreement that we both think is fair...opinions please!