(CNN) Former first lady Barbara Bush is in failing health, a source close to the Bush family tells CNN.

The source said she is being cared for at her home in Houston and has decided she does not want to go back into the hospital. She has been on oxygen for some time.

Her husband, former President George H. W. Bush is with her, as are daughter Doro and sons Marvin and Neil. Her other sons, former President George W. Bush and former Gov. Jeb Bush, have been in and out visiting her the past week.

Bush's office released a statement, confirming after a "recent series of hospitalizations," she has decided against seeking additional medical help and will instead focus on "comfort care."

"It will not surprise those who know her that Barbara Bush has been a rock in the face of her failing health, worrying not for herself — thanks to her abiding faith — but for others. She is surrounded by a family she adores, and appreciates the many kind messages and especially the prayers she is receiving," the statement continued.

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