Princess Anne was hospitalized Sunday night after suffering horrific injuries at her home, Gatcombe Park, but in the aftermath of the accident, the princess could not remember what had happened. Princess Anne, sister of King Charles and only daughter of the late Queen Elizabeth and Prince Philip, suffered a concussion and subsequent memory loss, but fortunately, as royal writer Katie Nichol told "Entertainment Tonight," the memory loss was not long-term

"I'm not sure how long it will last.

"All we understand is that she doesn't remember the incident," Nicole said. Obviously, she was asked about what happened, but she simply does not remember." Nicole added, "There is no suggestion that this amnesia is anything more than the immediate aftermath of what happened."

According to Ann's medical team, she sustained a head injury from an impact by a horse's leg or hoof. Says Nicole, "It appears she was struck or kicked in the head by the horse." 'She was walking in a protected area of the park and obviously something happened.'

While Nicole noted that "any concussion can be very serious," Ann's husband, Sir Timothy Lawrence, told Wells that his wife is "recovering well, thank you. 'We are deeply appreciative of the professional care of our medical team and the support staff at the hospital. We are both deeply touched by the kind messages we have received from so many people near and far. It means a lot."

Anne has been in the hospital since Sunday night, and "she is still under surveillance, which I think suggests that they are not going to take any chances," Nicole said.

"The Palace has given guidelines that Princess Anne will likely spend most of this week in the hospital.

Princess Royal has been riding horses for years and is an Olympian. 'It's worth pointing out that she's had some pretty hairy experiences,' Nicole said. 'She's been thrown from a horse. She has been thrown off a horse. She has been knocked off her horse and knocked unconscious."

For Princess Anne, now 73, "I guess we can only hope it's not serious," Nicole said. 'But I think this feels like a very difficult time for the royal family, and I think it highlights the fact that we are a royal family [king, queen, and head of state], but we are ordinary people. The cancer (of the King, Prince Charles, Princess of Wales, and Sarah Ferguson, Duchess of York) was a great leveler. And as every family knows, accidents happen. It just feels like a lot happened at once."

As a result of the accident, Ann was unable to attend last night's state dinner in Japan and also had to cancel her planned Canadian tour.