If the photos were left to you in a will or assigned to you by the Court's division of her assets, yes.
Your local attorney can advise you whether you may have "standing" to petition the court to release conservator accounting information, absent any specific allegations or proof of malfeasance.
The executor has no power while the person is living. Until they are appointed by the court, they have no power.
America's Court with Judge Ross - 2010 My Brother's Keeper 1-177 was released on: USA: 14 April 2011
when or why? Mothers will lose custody if they are found unfit by a family court
America's Court with Judge Ross - 2010 Don't Call Security The Burnout Brother 3-109 was released on: USA: 2013
Judge Karen's Court - 2010 My Long-Lost Brother Broke My Heart 2-33 was released on: USA: 27 April 2011
Your question is asking about the rules of evidence. It's not as simple as admissible or not. The rules vary from place to place, court to court, but it also depends on who took the photos, what they are meant to show, and what the injury has to do with the actual case.
Legally, only with permission of the court.
Whomever applies to the court to replace him.
No, unless you have a power of attorney from your brother. And if your brother is deceased, you would have to be the executor of the estate and have the court's permission.
America's Court with Judge Ross - 2010 Chewing Gum Con Man Dead Beat Brother-in-Law 1-182 was released on: USA: 18 April 2011
He applies to the probate court for a letter of authority. The forms necessary will be available online or at the court house.