The pregnant actress sported a particularly frumpy skirt, striped Nora Batty-style long socks and wedge-heeled bovver boots on a trip out in London.
Oscar-nominated Helena, 41 - who is expecting her second child in December with film director Tim Burton - appeared to be practising her deep-breathing techniques.
For the star, the ensemble was just another example of her 'shambles chic' that has seen the Harry Potter actress become a regular in the worst-dressed fashion lists.
Ironically, Helena built her career playing well dressed and tightly-bodiced women in Eighties period costume dramas such as Howards End and Room With A View.
But fashion expert Karen Kay said: "Outside movies, Helena has never been known for a polished sense of style and could politely be described as an English eccentric.
"Dressing through pregnancy was always going to throw up some interesting concoctions."
I've always kind of loved her but I now have a slight girl crush on her after OOTP. This pic makes me laugh.