Who's Claire Bloom?

In an interview with The Times veteran actress Claire Bloom (best known to SF&F fans as Hera in Clash Of The Titans) has dropped some hints about her role in Doctor Who’s "The End Of Time".
When asked if there is any truth in the rumours that that she is playing the Doctor’s mother, she replied, “Possibly his mother, possibly not, someone who appears and basically gives him the bad news. A seer, a prophetess. Also she is somehow there as a protectress. But that’s more in what I tried to do than in the script. The scripts are very, very complicated.”