Transcript for Excitement erupts over Princess Kate's royal pregnancy
William and Kate, bookies already taking bets on the name. Favorites are Alice and Arthur. Amy got a lot more. That's right. No matter what baby number three is named, he or she has already claimed their place in line for the throne bumping their uncle prince Harry down in the succession line and prince William saying there's not much sleep going on at home but he and Kate are celebrating the very happy news. It's soon to be a party of five for prince William and Kate with baby number three on the way for the royal couple. Everyone here in this country is very excited about, you know, a royal baby and birth is a big dial. Reporter: Coming earlier than palace officials were anticipating after it was revealed that Kate is again suffering from hyperemesis gravidarum, sometimes described as acute morning sickness. Doctors warn the condition can become dangerous causing severe malnutrition, electrolyte abnormalities and in some cases even organ failure. We know at this time it's not as severe as the first pregnancy because she's not been admitted to hospital but she's incredibly unwell and would like to take prince George to his first day of school Thursday but royal aides have said she'll probably decide 0 the morning. Kate hinting in July at a growing family after a well Weishar gave her a gift meant for a newborn baby. We'll just have to have more babies. Reporter: Baby number three bumps prince Harry down to sixth in line of succession and thanks to a law change in 2013 princess Charlotte will remain fourth in line just behind big brother George regardless of what whether or not the new baby is a boy or a girl. Uncle Harry was all smiles stepping out in Manchester Monday. Fantastic. Great. Very, very happy for them. Reporter: Next in line poised to help grow the royal family, prince Harry's girlfriend, actress Meghan Markle in a new candid interview with "Vanity fair" Markle opening up about their relationship amid engagement speculation, a love story that started in may of 2016 at Harry's charity event the invictus games. The "Suit" star saying we're two people who are happy and in love. Nothing about me changed. I'm still the same person that I am and I've never defined myself by my relationship. When we see him in a few weeks in Toronto at the invictus games she'll be there. Her first chance to experience what that intense media scrutiny is like and I think probably from invictus onwards we will see more of her appearing by his side. Reporter: With regards to keeping it private, Markle says, I hope what people will understand is that this is our time. This is for us. It's part of what makes it so special that it's just ours. But we're happy. Personally, I love a great love story. Harry would not want an engagement announcement to detract from what they're doing there but I suspect we may soon get an announcement possibly before Christmas. Oh, see, we all love a great love story but the queen still gets to weigh in. Po worth pointing out that rule that changed, the seventh in line to the throne doesn't need the queen's permission to marry. Harry is about to be number six so he still has to apk before making that proposal to Markle and, you know, Lara, so many exciting potential news coming out of -- Book the ticket already. I would like to take us back. Remember this photo, Lara. Oh. This is us waiting for the news that prince George was born. In the pouring rain. Four years ago, a huge awesome London storm decided to shower us with love. He's starting primary school next week. Where does the time go. It's amazing. Now he's big, big brother. This is exciting. We will be there, ABC news. Happy to go. We got to go. You all have your tickets
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