The transgender soldier is due to face a closed hearing on Tuesday to determine her fate, they add.
The military has not yet commented.
The soldier, formerly known as Bradley Manning, was convicted in 2013 for leaking thousands of secret US files to the whistle-blowing website Wikileaks.
She is currently serving a 35-year jail sentence at a military prison in Fort Leavenworth, Kansas.
Manning's lawyers revealed the possible disciplinary action on Wednesday.
"Frankly it looks to me like harassment," one of her lawyers, Nancy Hollander, told the Associated Press news agency.
She said the ex-intelligence analyst has been accused of possession of prohibited property while in military prison, including books and magazines.
A Vanity Fair issue with transgender Caitlyn Jenner (formerly known as Bruce) on the cover and Malala Yousafzai's memoir were among the items allegedly discovered in her prison cell.
Misuse of medicine - namely an expired tube of toothpaste, sweeping food onto the floor and disrespect - were some of the other charges cited.
"It is not uncommon in prisons to have charges that to the rest of us seem to be absurd," Mrs Hollander told AP.
"Prisons are very controlled environments and they try to keep them very controlled and sometimes in that control they really go too far and I think that this is going too far."
The maximum punishment Manning could face is indefinite solitary confinement. Manning has requested the disciplinary hearing be made public next Tuesday, her lawyers say.
Meanwhile, a petition has been set up by her supporters calling for her hearing to be "open to the public and the press".
Manning, who legally changed her name in 2014, remains a soldier until her prison term ends. She recently debuted as a contributing writer for the Guardian US website.
Earlier this year, she was approved for hormone therapy after being diagnosed with gender dysphoria -  the sense of one's gender being at odds with the sex assigned at birth.
US Army whistleblower Pte Chelsea Manning may face solitary confinement for allegedly violating prison rules by having a copy of Vanity Fair and expired toothpaste, her lawyers say.