2:44 PM PT -- Mary Lou Retton's daughter, McKenna Kelley, just updated fans about her mom via Instagram ... saying she's still in the ICU and continues to fight.

"She is getting incredible medical care! Thank you to all the doctors and nurses!"

Kelley -- along with her three sisters Skyla, Shayla, and Emma -- also thanked everyone for their love and support.

"We ask for continued prayers and positive thoughts for our mom."

The SpotFundMe has also increased to over $285k!

9:29 AM PT -- The fundraiser for Mary Lou Retton has now hit a quarter-million dollars ... with famous Texas businessman Jim "Mattress Mack" McIngvale's wife, Linda donating an astounding $50,000.

The financial support is pouring in for Olympics legend Mary Lou Retton ... with more than $181k in donations being collected as she battles a serious medical issue.

As we previously reported, the gold medalist has been in the ICU fighting for her life as she deals with a "very rare form of pneumonia," according to her daughter ... and she is currently unable to breathe on her own.

Considering 55-year-old MLR is uninsured, the family started a SpotFund page to help with medical bills ... and shortly after the fundraiser went live, it shattered its goal of $50,000.

In fact, the cause has raised more than triple the original goal as of Wednesday morning ... and it only continues to rise.

So far, more than 3,900 people have donated to Retton's expenses ... with many leaving words of support for the gymnast and her family.

Retton is one of the most popular American Olympians from the '80s ... earning gold in the all-around, as well as a pair of silver and bronze medals, in 1984.

Now, her fans throughout the country are pulling for her once again.