The former couple have five other children alongside the teen, who filed for the name change on her 18th birthday, May 27.
The alteration was announced with a legally obligated public notice in the Los Angeles Times shortly after her move.
Angelina Jolie and Brad Pitt's children include (L-R) Shiloh, Zahara, Vivienne, Maddox and Knox. (AP PHOTO)
In a new statement, Shiloh Jolie's lawyer Peter Levine called it a "significant decision" and said people should be careful about how they report the change, stressing his client never took out an "ad" to publicise it.
"The media should be more careful in their reporting, especially when covering a young adult who has made an independent and significant decision following painful events, and is merely following legal process," Levine said.
"Shiloh Jolie did not take out an 'ad' announcing any name change, and any press reporting that is inaccurate.
"As Shiloh's attorney, I am required to publish a legal notice because the law in California requires that of anyone who wants to change their name."
His comments echo those made by California-based family lawyer David Glass, who told People the public name-change announcement could not have been avoided.
"She has to file a formal petition with the court to change her name, and she has to run an ad four weeks in a row before the hearing is scheduled, in addition to giving both of her parents written notification," Glass said.
"These name change petitions usually run very smoothly and are granted, unless the person has a criminal history and is trying to get away from punishment or liabilities … (I've) never seen one opposed in court.
"Brad could come to court and say, for example, that Shiloh has been alienated against him by the mother. But because she is no longer a minor, she can essentially call herself whatever she wants."
Brad Pitt has virtually no contact with his adult children, according to a source. (EPA PHOTO)
Angelina Jolie, 49, and Pitt, 60, split in 2016. Their children are Shiloh, Maddox, 22, Pax, 20, Zahara, 19, and 16-year-old twins Knox and Vivienne.
A source told People that Fight Club actor Pitt, who is dating businesswoman Ines de Ramon, 31, now has "virtually no contact with the adult kids".
Another insider told the outlet the actor "still loves all of his kids tremendously".