Please read the following paragraph, I can not figure out the meaning of the word "shadow",please help.
the following text is extracted from the article at this web address.
The Guardian profile: Ruth Kelly | UK news | The Guardian
Even political opponents speak of her warmth, charm and reasonableness. "She has a disarming style about her which makes it difficult for political opponents to deal with her," said David Laws, the Liberal Democrat Treasury spokesman who shadowed her in her role as financial secretary "She just about gets the balance right between sticking to the government message and sounding as if she might be a human individual - not a speak-your-weight machine, which some of the ministers do."
what does shadow mean?
to follow someone closely in order to watch what they are doing