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Molly Weasley, Ron's mother is always portrayed as a kind,motherly character in most of the contexts in the series.An affectionate,but short-tempered woman when it comes to her kids, she is mostly shown to be a home-maker.
Referring to the books of Gilderoy Lockhart for house-hold spells or Falling prey to the Boggart emotionally in The Harry Potter and the order of Phoenix show that she is not a fighter kind of woman as whom she is portrayed towards the end.
Guarding the 'weapon' in the Harry Potter and the Order of Phoenix .
She would have written all this to you, but if the owl had been intercepted you’d all have been in real trouble, and she can’t say it for herself because she’s on duty tonight.” “On duty doing what?” said Ron quickly. “Never you mind, just stuff for the Order,” said Sirius. “
or killing of Bellatrix Lestrange, a woman who has a sophisticated knowledge of Dark Arts, who has a record of torturing well-trained aurors(the Longbottoms), who has killed Sirius Black.
“No!” Mrs. Weasley cried as a few students ran forward, trying to come to her aid. “Get back! Get back! She is mine!” Molly’s curse soared beneath Bellatrix’s outstretched arm and hit her squarely in the chest, directly over her heart.
Sudden change of intensity of the character does not seem fitting. or does it?