She’s going to be the best sister-in-law ever! Kate Middleton will soon help the royal family welcome Meghan Markle as one of their own — and will start off by throwing Prince Harry‘s fiancée the ultimate bachelorette party. A source close to the situation revealed Prince William‘s pregnant wife “pulled out all the stops” to make sure her last hoorah as a single lady goes well.

The festivities will include lots of wine and Dom Perignon champagne, a photo booth, and karaoke. “Kate is determined to make it an unforgettable occasion,” an insider told In Touch, adding “there will be no expense spared” over the big weekend. “She wants Meghan to be reminiscing about it for years to come.”

And that’s not all! The source also divulged that William and Harry’s grandmother, Queen Elizabeth II, will find her own way to join the fun. While she won’t be present, “those close to Meghan are already betting that the queen will surprise Meghan with some sexy underthings” while the other guests “will surprise Meghan with fun presents, including sexy Agent Provocateur lingerie and X-rated baked goods.” We can’t lie — this is all giving us a serious case of #FOMO!

Prince Harry and the former Suits star announced their engagement in November 2017. They first sparked romance rumors back in 2016 and plan to wed on May 19 of this year. Meghan seems to be fitting in the royal family quite well, particularly with the Duchess of Cambridge — with whom she’s really formed a bond with since dating Harry.

“Kate has taken Meghan under her wing and is really looking out for her,” a source told Life & Style back in January. “She’s advising her new BFF on how to deal with what lies ahead. They’ve become super close.”