
Continuity mistake: In the flashback to the death of the headless horseman, when the horseman's steed gets shot and falls to the ground, the blood and the wound are on the right side of the horse...later in the scene when the horse is seen again, the wound is on the left side of the horse. (00:16:45)
Answer: As revealed by Lady Van Tassel to Katrina during the film's climax, the midwife Mrs. Killian was abreast of the secrets regarding the affairs of Peter Van Garrett with the widow Winship, as well as their unborn child. Mrs. Killian revealed this secret to Lady Van Tassel right in front of Mr. Killian, which signed both of their death warrants. However, Lady Van Tassel most likely commanded the Headless Horseman to kill the Killians (as opposed to just saying Mr. & Mrs. Killian), to which the Horseman would instinctively murder their child too. It may have been an oversight on the part of Lady Van Tassel, as the child would undoubtedly be ignorant of affairs and the intricacies of legal matters regarding wills, but then again, she probably didn't care anyway.
Phaneron ★