MY wife follows my grandmother in making a baked suet pudding for roast as opposed to the light airy fairy yorkshires. With your grandmother doing similar it is probably an age thing brought about by rationing and the war..
Traditionally the veg is Sprouts carrots and peas to go with the roast tatties but I cant see why you cant have whatever you like. At any roast my wife does Swede and to me a roast isnt complete without beans of some description either Runners or Broad from the allotment that I have frozen or...