It looks very much like her brother's painting of the sisters that hangs in the National Portrait Gallery in London. So, it must bear a strong resemblance to the real person. Of course, for those of us who know and admire the Brontes, Charlotte was a stalker. Her “unrequited” love involved driving her poor, married Belgian teacher nuts as she stalked him all around Brussels, sending him love notes, having meltdowns and badgering his wife until he hid from her. Thackeray hid from her too, not because she was smitten with him, but he couldn't stand her Hillary-like personality.
Of course, she was a literary genius but I much prefer her wild and impetuous and granite-like sister, Emily.