Melanie Smith will be sentenced on 8 May for murdering five members of the same family in a flat fire in Prestatyn.
Mr Justice Griffith-Williams warned the 43-year-old that she should expect a life sentence.
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A cold night but temperatures remain above zero
Watch our report on events held to mark 'White Ribbon Day' - and access information and advice on domestic abuse and how to get help.
Outbreaks of rain will continue through the night, turning heavy in places