Melanie Jane Smith is due to appear before magistrates in Prestatyn on Tuesday morning in connection with a house fire in Prestatyn.
The 42-year-old was charged with four counts of murder, one count of arson with intent to endanger life and threats to commit criminal damage yesterday.
Lee-Anna Shiers died in the fire along with her niece and nephew Bailey and Skye Allen. 15-month-old Charlie Timbrell died from burns suffered in the fire at Liverpool's Alder Hay Hospital.
More top news
Missed tonight's Wales at Six? Catch up here.
A man is in police custody after he was seen in possession with a knife in Pontardawe.
It'll stay dry tonight with clear skies developing. Some light and patchy mist and fog may form overnight.