The "multi-million" claim from that Politics UK link is for a plot of land he bought next to his house in Surrey in the 1990s, when it would have been worth considerably less. It's a bit like accusing all the pensioners still living in their homes in the Home Counties of being multi-millionaires. Asset inflation has been horrible for this country and I'd love to see a way out of it that wouldn't involve complete economic Armageddon, but Starner's hardly alone in having a property that's ballooned in value over the past 20 years.
The same fact check goes on to say this:
"Unlike many politicians,Sir Keir Starmer was not born into a life of privilege. Starmer was born in Southwark. His father, Rodney Starmer, was a toolmaker and his mother was a nurse. He was later educated at Reigate Grammar School in Surrey."
I liked the red dress, personally. Pretty, modest, and didn't try too hard.