Ms Mahomes told her more than 277,000 followers on Twitter that she was still building a house while pregnant with the Kansas City Chiefs’s second child.
The pair married earlier this year and have one child, Sterling.
Ms Mahomes tweeted: “Started with building a house when I was pregnant with Sterling, I am now about to have another child and….still working on the house life is fun!”
Her followers and other users on Twitter mocked the professional trainer for her comments on the same day Hurricane Ian made landfall as a Category 4 storm on Wednesday.
Hundreds of thousands of Florida residents are without power, many coastal cities remain flooded and at least 68 deaths have been confirmed across the southern US state, North Carolina and in Cuba.
Tweeting at Mr Mahomes, one Twitter user wrote: “Peoples homes are getting destroyed in Florida and this is what your wife decides to say? Tell her to get rid of her social media account. She can’t be this dumb. Does she think before she tweets stuff?”
Another argued: “H’ow freaking tone deaf are you?? There is a massive hurricane destroying peoples homes this very minute! Read the room and delete this tweet bragging about your privilege! You are vile!!”
“Well, many lost their homes due to the hurricane, so at least you have a roof over your head now,” a third person tweeted.
Not all replies were negative however, with many other Twitter users defending Ms Mahomes.
“The amount of people commenting negative things towards her because she’s talking about HER HOME is ridiculous!” argued one Twitter user. “So she can’t be happy because of a hurricane in Florida!? Make it make sense…”
Another person added: “The hate she gets plus her family is never ending! Keep being you Brittany! They just mad cause they aren’t working their asses off like you with your business!”
In February, Mahomes was forced to defend his then-finance from reports that he had asked her to stay away from Kansas City Chief games, a claim he said was fabricated.
“Y’all just be making stuff up these days,” the NFL star tweeted at the time, while calling such claims and reports about Ms Mahomes “hysterical”.