It should be the happiest time of her life.

But as Natascha McElhone prepares for the birth of her third baby she is doing so alone.

The heavily pregnant actress cut a lonely figure during a low-key outing in London.

The 36-year-old is still coming to terms with the loss of her husband-of-ten-years, Martin Kelly, who died three months ago.

Brave face: Heavily pregnant Natascha McElhone in London today

As she emerged into the September sunshine after parking near her West London townhouse, she showed off a pronounced bump covered by a flowing red dress and matching cardigan.

The Californication star, already has two sons by her late husband Theo, eight, and Otis, five. The plastic surgeon has jokingly named their expected new arrival 'K3'.

She was left 'absolutely devastated' after 43-year-old Kelly was found collapsed in the hall of their £2.5million townhouse in London, just after performing a late-night operation.

Waiting for baby: The actress is expecting her third child

He died as a result of 'dilated cardiomyopathy', where the heart becomes enlarged and cannot pump blood efficiently.

The couple were about to celebrate their tenth wedding anniversary and had known each other since they were teenagers.

After his death, she said: 'I just can’t believe I won’t feel his skin any more, how is that possible? I loved and touched him every day, and thank goodness I did. 

'The part that saddens me most is that, whatever I can try to give my boys, their world for now has been halved, I cannot become him.

So in love: Natascha with husband Martin, who died in May, at a party in 2003

'All I can hope is that the seeds have been sown already in their short lives – their gardens will flourish and I will tend to them assiduously and find any way I can to fill the gaping crevices.'

Mr Kelly was feted for his charity work in rebuilding the faces of disfigured Third World children and his celebrity cases, including repairing the cocaine-ravaged nose of Tara Palmer Tomkinson.