What are consequences if co-executors are disagreeing?

Sister and brother named co-executors. Both retain estate attorney together. Then sister keeps contacting the attorney without consulting the brother. Attorney does not include brother in emails or discussions. Second brother finds out that the sister takes valuable jewelry and distributes between herself and two sisters, leaving out the fourth sister and two brothers. Second brother finds out she did this, gets an attorney to have her removed as co-executor. After the sister is notified of attorney, she then states she only took jewelry to have it appraised but never notifying co-executor she was doing this. She changed her story three times.