The presenter was a no-show on the ITV morning show on Wednesday and Thursday and viewers were given no explanation why.
Holly has now revealed that two of her children became ill with Covid-19 symptoms.
The mum-of-three updated fans in an Instagram post shared on Saturday.
“Just wanted to say thank you for all your kind messages. Over the last few days two of our children were unwell and had symptoms of Covid,” she explained.
“In line with government guidelines we were waiting for results of the tests before I return to work.
“Couple that with just wanting to look after two poorly children, it meant having two days away from This Morning.”
“I chose not to alert everyone to this because my focus was on looking after them.
“Thankfully all tests came back negative and everybody’s feeling much better... see you Monday!”
Holly was also tested, despite having no symptoms, and the family received the all-clear last night – meaning the 39-year-old will be back on our screens presenting This Morning on Monday.
Holly shares children Harry, 11, Belle, nine, and Chester, five, with producer husband Dan Baldwin.
In her absence, Alison Hammond and Davina McCall were called in at the last minute to co-present the show with regular host Phillip Schofield.