I've seen the original stage version and I can't help it Mrs Lovette is not Helana Bonam Carter. I know she sleeps with the director which I'm sure helps to get parts but I just think someone could have done it so much better. She really couldn't get the humour in the songs.
This is a
clip of the original Mrs Lovette. Ignore the crap costume and the rubbish Sweeney Todd etc and yes that is the woman from Murder She Wrote and Bednobs and Broomsticks. She is amazing! I think if toned down a bit for the film her performance is far better than Carters. But then again I'm a bit of a musicals geek and I think some of the humour was lost in the film.