How Meghan Markle and Kate Middleton's Bond Is Growing (Exclusive)

Ahead of the royal wedding, the 'Suits' actress is forging a close connection with her future sister-in-law.

Meghan Markle and her future sister-in-law, Kate Middleton, are growing closer every day as the Suits star continues to adjust to her life as a royal.

"Kate has been doing whatever she can to help Meghan adjust to life behind Palace walls," a source tells ET. "Of course with two little ones, and a third on the way, Kate has her hands full, but she’s been guiding Meghan on Palace protocol and supporting her."

As Markle and Middleton's bond has been growing increasingly strong, Prince Harry's bride-to-be has been doing everything she can to ingratiate herself into the family before the wedding, even bringing her in-laws some home cooked food.

"An avid cook, Meghan often pops around to visit with Kate and the kids dropping off treats," the source says. "Meghan has also been leaning on Kate for advice as she joins the Royal family."

It's not just advice that the 36-year-old actress has been getting from the Duchess of Cambridge. As Markle's circle of friends gets smaller and her responsibilities require her to spend much more time in England, she's been looking to Middleton for friendship as much as anything else.

"Meghan has also turned to Kate to keep her company as she has less flexibility roaming around freely since joining life as a future member of the Royal Family," the source shares. "Meghan is adapting to a life without her social media accounts, under the constant scrutiny of the paparazzi, with help from Kate."

While the two may be forging quite a strong connection, the source says Meghan won't be looking to Kate to serve as her maid of honor, but instead will "choose one of her closest friends who has stood by her for many years before meeting Harry." However, the source did not say which friend Markle is expected to ask.

Markle is apparently enjoying a lot of love and support from the entire royal family as her wedding to Prince Harry approaches. Royal expert Katie Nicholl, author of Harry: Life, Loss, and Love, exclusively told ET this week that the Queen is very supportive of Harry's relationship with his gorgeous lady love, despite her non-traditional background.

"One of the things I was really keen to trying to get to the bottom of in the book was how the Queen really felt about Meghan," Nicholl explained. "She's filmed some pretty racy sex scenes that we've all seen in Suits. Everything from being a divorcee to being a bit older then Prince Harry, to coming from a dual heritage family, you might wonder if the Queen being of a certain generation and, of course, being the queen might have been at all concerned."

"But everything I heard from the sources I spoke to was that she really felt from the outset that Meghan was a positive person in Prince Harry's life," Nicholl shared. "That she made him very happy and that she was really very supportive."

Check out the video below to hear more on the upcoming and highly anticipated royal wedding on May 19.