Looks too BBC?
You mean she looks like a Redgrave or a Richardson. Not to disparage her, but if you wanted a Redgrave or a Richardson and you couldn't get one, you might wind up with the first actor who looked like one. Perhaps those dynasties have had the effect of spawning a generation of lookalikes.
See Jemma Redgrave's turn as Kate Stewart, and indeed the spin-off portrayal.