Do I have to pay stamp duty on a transfer of property where inheritance is involved?

I have been left a 50% share in my fathers house the other 50% is my sisters - so that's approxirately £200,000 each.  Her own house is worth £300,000. She would like my fathers house and I am happy for her to buy me out. Can I just give her £100,000 and she transfer her property to me, and then she will own my dads house outright and I will own hers? What stamp duty am I liable for if she just transfers to me the ownership and I pay her £100,000 in lieu of my share of inheritance? Would I have to pay stamp duty on the whole value £300,000?