New mom Serena Williams has penned a heartwarming letter to her mother in which she explains that seeing her daughter's resemblance to her body structure has made her realise her mom's strength.

In the letter shared on social media, Serena explained that her newborn daughter made her view things in a different light. This included her insecurities and fears that her baby girl may also be subjected to body shaming.

Serena started the letter by hailing her mom's strength.

"I was looking at my daughter and she has my arms and legs! My exact same strong, muscular, powerful, sensational arms and body. I don't know how I would react if she has to go through what I've gone through since I was a 15-year-old and even to this day," she wrote.

The tennis champ recalled how she was criticised over her body, was accused of taking enhancement drugs and being told many times that she belonged in "men's sport".

"I've been called a man because I appeared outwardly strong. It has been said that I use drugs (No, I have always had far too much integrity to behave dishonestly in order to gain an advantage). It has been said I don't belong in women's sports, that I belong in men's, because I look stronger than many other women do," she said.

Serena said she is proud of the way her mom helped her handle the criticism and is grateful for the self-pride instilled in her.

"I am proud we were able to show them what some women look like. We don't all look the same. We are curvy, strong, muscular, tall, small, just to name a few, and all the same: we are women and proud! You are so classy, I only wish I could take your lead," she added.

The tennis player said she hoped to teach her daughter the values her mother taught her and asked her mom to continue holding her hand through the process.

"Thank you for being the role model I needed to endure all the hardships that I now regard as a challenges- ones that I enjoy. I hope to teach my baby Alexis Olympia the same, and have the same fortitude you have had."

Serena and her fiancé, Reddit co-founder Alexis Ohanian, welcomed their daughter, Alexis Olympia Ohanian Jr., on September 1.