Several newspapers have named former Bill actor Huw Higginson as the father of her unborn child.
Hannah, who is 35, has remained resolutely tight-lipped about her pregnancy, but reports yesterday claim she has been in a relationship with Mr Higginson for some time.
The actor is said to have left his wife and children and moved in with Miss Waterman as she nears her due date.
The couple briefly starred alongside each other in EastEnders 10 years ago.
A friend told reporters they were 'blissfully happy' and looking forward to their new arrival.
Miss Waterman separated from her husband, former EastEnders actor Ricky Groves, in 2009.
What do you think about this story?
Do you think Hannah will keep her pregnancy and birth private, or can you see a huge magazine reveal in the offing?
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