Den96912 low

Would like the proceeds of selling my home to go to my daughter as a GIFT to buy a bigger home for us all to reside in...how would this be possible ..I'm now widowed for some years and if i passed away would The current allowance which is £325,000 could this be combined to my late wifes £ 325,000 to a total of £650,000 worth of assets to be passed on after both of our deaths ie to my daughter/fiance and what other tax complications may arise..

my fiances father is selling hes home and gifting us the proceeds, we are currently renting, combined proceeds from fiances father and monies we have are going together to buy s new larger home with which we will all reside together the deeds will be in both my fiances name and mine, will we owe tax on the gift, or will I as hes not my father, the proceeds are not currently over the tax inheritance threshold.