Rebecca hadn't noticed Clara playing with the matches. She hadn't noticed her success in lighting one, her shock at lighting it, or the fact that she dropped it. The only thing that Rebecca noticed was the scent of burning hair and the fact it suddenly got just a little bit warmer. And brighter.
By the time she noticed exactly what was wrong, it was already too late for the coat. She turned around to see a small flame, about the size of her palm, burning the hem of her coat. Her favorite mink coat. "Put it out! Put it out!" She quickly slid the sleeves off of her arms and jumped to her feet. How did muggles put out fires? Nevermind about making them.