Voting Question: Should i take the money?

When my nan passed away(mums mum) she left everything to my mum, when my mum passed away she did not have a will so everything went to my dad but he still wanting the inheritence asked my mums daughter(not my dads)to do the probate and signed everything over to her, when completed she gave me half of the total she did not tell my dad her intentions, i was shocked and upset she had lied to my dad, i then went to a solicitor with my dad and gave the cheque which was in my name to the solicitor because my dad wants to try and get it all back, in the couple of years that has passed my dad no longer bothers with me or my children as he has a new partner, can i and should i ask for my cheque back it is for £40,000 so pretty life changing but don’t know where i stand legallly dont know what to do morally?
its not my dad that has my cheque it is the solicitors sorry don’t think i explained it right! He signed it all over to my half sister who gave me half but morally i thought it was wrong so i was going to give it to my dad but i think i should ask for my cheque back now hope thats a bit more understandable:-)