I'm sorry, OP, the situation seems awful.
I think most people (not the 'entitled' critics) seem to be worried you will disadvantage yourself in seeking fairness. At very best, the law is an imprecise and expensive tool. Your posts clearly show your focus on fairness and the law will usually leave a challenger to a will worse off. I don't know the circumstances but equally you might be fighting the solicitor who took the will who will have more resources and the executor/beneficiaries too. It's unlikely your solicitor will tell you that you have 'no chance' so if that is the question you ask, you are likely to end up down an expensive route. Further to my previous post when I suggested you ask your solicitor what their strategy would be, including negotiating to reinstate you and your DSis through an agreed deed of variation, you might want to ask your solicitor for an illustrative decision tree or similar, showing the broadest outcomes, the estimate of probability and the likely costs to you. So you can see their estimate of the chance of:
negotiating a settlement:
going to court and winning; and
losing, and how much these options (and any others) are likely to cost.
Your solicitor might not want to do this but it would give you a sense check and something to check with other people. The solicitor is running a hsuiness but also has some professional obligations.
I can see you seem focused on fairness rather than the money but I think this might show you the eye watering costs and likelihood of losing.
One final point, it might be an idea to explore whether your DParents' wills were a particular kind of mirror wills that, in some circumstances, might have been 'set in stone' and should have been unchangeable after the passing of the first DParent - there is some case law if you are in England and Wales. If that was the case, it might be easier to argue the new will should be set aside and negotiate the deed of variation that would be the cheapest way of resolving this.
Good luck.