I sank like a stone
into the still, deep waters of late middle age,
aching from head to foot
I took up food
and gave up exercise.
It did me good.
And while he slept
I found some hobbies for myself.
Painting. Seeing the sights I'd always dreamed about:
The Leaning Tower.
There are various interpretations of sleep in  fairy tales . In some sleeping implies laziness; in others it symbolises escape. Here it is not Rip Van Winkle who needs the escape but his wife. His long sleep is a godsend to her. 
 Carol Ann Duffy is no doubt making a pointed reference to the plight of many middle-aged women.  After years of hard work, maybe raising three or four children, contributing to the household income with low paid work, caring for two sets of elderly parents and taking on the burden of worry for the whole family, many women are exhausted. Added to this may be ill health, the menopause and a selfish, inconsiderate or even straying husband. It is unsurprising that many, like Mrs Van Winkle who ‘sank like a stone’, suffer depression and exhaustion.
Mrs Rip Van Winkle