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I would put money on that being Shoebox Zoo. The girl's name was Marnie and she had just moved from the US to Edinburgh to live with her father and she acquired a shoebox with four animal figurines in it - an eagle, a snake, a wolf and a bear - who were really the transformed students of the wizard Micheal Scot (who IRL was a mathmatician and philosopher more than a wizard...) who are trapped in these forms for stealing The Book of Forbidden Knowledge so they want the book in order to change back. They were hindered in this by a villian named Toledo who wanted the Book to take over the world. And the number eleven was al over the place - Marnie gets the shoebox on her 11th birthday, the students are 1100 years old, and a bunch of other stuff that I can't immediately recall. Series two had Marnie return to America to stay with her grandparents where she met another small animal that I'm pretty sure was a horse and had some kind of mystical Native American connections.
The Shoebox Zoo themselves were voiced by Rik Mayall, Siobhan Redmond, Simon Callow and Alan Cumming. IMDB page here: http://www.imdb.com/title/tt0406468/

I remember watching some kids show which centred around an 11 year old girl who was chasing some book which the help of some tiny monsters (7 I think). I remember the number 11 was critical to the plot in all sorts of ways.