Bad mistake: *Ex-Tory MP apologises for ancestors' links to slavery.*
You should never apologize for things others have done for which you
are not responsible.
Aside from that, what she did was proper. She acknowledged the
ancestors' actions, which had been unknown to her until a historian
dug them up in old records, and she denounced them. That is the right
thing for anyone to do who has as little responsibility for those
actions as she has.
It is horrible that people have made death threats against her for
things someone else did long ago. Advocating Tory policies entails
moral responsibility for them (though not for slavery hundreds of
years ago), but it doesn't justify threats of violence.