SM Entertainment has shared an article about Red Velvet's Wendy's well-being.

Wendy fell from the stage while choreographing on SBS Gayo Daejeon at the Gocheok Sky Dome in Seoul on December 25, 2019. Her face suffered from wounds and her pelvis and wrist were fractured. Since then, she was hospitalized and has taken a sat out Red Velvet's events and activities.
A representative from her label SM Entertainment reported on April 3 that she was released from the hospital and stated, "Wendy's condition has greatly improved but she's still undergoing outpatient treatment."

After the accident happened, SM Entertainment previously shared the details about her Injury through every media outlet news.
According to No Cut News, a source from the agency reported, "Wendy fell off the stage and suffered injuries during practice sessions for her individual appearance for 2019 SBS Gayo Daejeon."
They proceeded to say, "Wendy was rushed to the hospital promptly for a careful examination, and on the right side of her body she suffered bruises to her face and fractures in her pelvis and brace. She has received emergency medical treatment and now awaits further examinations. We will concentrate on her recovery as her safety comes first."

Further, they said, "We will release a statement about the forthcoming schedule of Red Velvet once everything has been worked out."
SBS also made a public statement saying, "There was an unfortunate turn of events during the 2019 SBS Gayo Daejeon practice sessions on December 25 that escalated to Red Velvet's Wendy suffering injuries."
They went on to say, "As an outcome, Red Velvet will be unable to participate in the 2019 SBS Gayo Daejeon live program, and we apologize deeply to the fans and viewers. We pray Red Velvet's Wendy will recover soon, and SBS will be more vigilant in maintaining security in the future."

Wendy posted a direct message to fans for the first time since being hospitalized on her birthday February 21. Not only did she acknowledge fans for their good wishes in her post as her birthday is on February 21, she also gave an update about how her treatment has progressed.
Read her message below.
View this post on InstagramHappiness~ 안녕하세요 레드벨벳의 웬디입니다~ 오랜만이죠 여러분? 놀라셨나용?? 두달만에 이렇게 게시물을 올리게 되는 것 같은데요~ 21일인 오늘 제 생일을 축하해주셔서 너무 감사드려요~ 그리고 여러분들의 걱정과 사랑 덕분에 잘 회복하고 있고 좋아지고 있답니다~ 많이 놀라게 해드리고 걱정시켜 드린거 같아서 미안해요 벌써 2월도 다 지나가고 있네요. 시간이 느린 것 같으면서도 빠른 것 같기도 하구..ㅎㅎ 우리 러비들~ 인스타 라이브 때 말했던 것 처럼 전 어디 안 가고 여기 그대로 있을거에요~ 평생 노래할꺼니깐요~ 그러니깐 빨리 회복해서 건강한 모습으로 무대에서 만날 수 있도록 할게요! 그동안 매일 매일 행복한 날들만 보내고 계세요!! 언제나 정말 많이 고맙고 좋아해요 우리 러비들 아주 많이 보고싶어요~ A post shared by Wendy (@todayis_wendy) on Feb 21, 2020 at 1:57am PST
"Happiness!
Yeah, it's Wendy from Red Velvet. It was a long time ago, right? Were you taken by surprise?
I believe I'm writing in two months, for the very first time. Thank you so much for remembering today 21 February my birthday. And I am doing well, and feeling much better, thanks to your care and encouragement.
I'm sorry I feel like I've scared you and had you worried. February is now coming to an end. Time feels like it is simultaneously moving slowly but quickly.
Our ReVeluv, as I have said before live in my Instagram, I am not heading somewhere and I will be right here. And I will sing for the rest of my life. And I'll get back up quickly so I can reach you in good physical health on stage as soon as possible!
Prior till then, spend happiness every day!
I am so thankful and I love you all the time, our ReVeluv. I miss you a lot."