Kate Middleton
Alicia Silverston penned a touching letter for a pregnant Kate Middleton. Pictured: Middleton visits The Sunken Garden at Kensington Palace on Aug. 30, 2017 in London. Getty Images/Chris Jackson

Alicia Silverstone recently showed her support for Kate Middleton.

The Duchess of Cambridge suffered from hyperemesis gravidarum or severe morning sickness during the early stages of her pregnancy. The condition kept her from fulfilling her royal duties. But the royal mom seems to have recovered as she was recently seen making surprise appearances at public events with Prince William and Prince Harry.

Silverstone knows that pregnancy is not easy, so she penned a touching letter for Middleton to show her support to the mom-of-two, OK! Magazine reported. She also offered a piece advice to help her cope with her struggles during her pregnancy and gave Middleton a copy of one of her books.

"Congratulations on the impending arrival of your third child! I imagine that Prince George and Princess Charlotte are thrilled at the idea of a new little brother or sister," Silverstone's letter read. "I was sorry to hear that you're once again suffering from severe morning sickness. With the hope of supporting you during this time, please accept a copy of my book 'The Kind Mama.'"

The "Clueless" star confessed that she wrote the book because she found a number of beautiful stories about pregnancy, birth and motherhood. Silverstone stressed that those stories were in contrast to what many have come to accept as normal like lower fertility, pregnancy ailments, less than ideal deliveries and more. The actress added that she consulted a variety of medical experts while working on her book. Those professionals helped her find ways to "ward off the symptoms that take away from an enjoyable pregnancy."

"Embracing this kind way and getting your body as healthy as possible will allow you to enjoy a smoother pregnancy," Silverstone wrote. "Ultimately, my hope for you is the same for all women who read this book: That you feel like you have a trusted resource and fellow mama to guide and reassure you along the way."

Middleton was on a strict bed rest last month, but she has been more active these past few days. On Oct. 10, she celebrated World Mental Health day with Prince William and Prince Harry, where she debuted her baby bump. However, a number of critics bump-shamed the royal, noting that her baby bump appeared to be very tiny.

Last week, she was also seen in a number of royal engagements. Last Monday, she danced with Paddington Bear at the Paddington Station. On Wednesday, Middleton, along with her husband and Prince Harry, visited the West Ham stadium for the We Are Coach Core event.

What can you say about Silverstone's letter for Middleton? Drop a comment below.