SAN ANTONIO -- The youngest suspect in the case of missing teacher Diane Tilly made her first court appearance Monday, as some of the teacher's students reacted with anger and confusion at the suspect's young age.

Tilly was a popular teacher and "didn't deserve this," said Courtney Touchette, a student at Robbins Academy, where Tilly was lead teacher. Robbins is part of the Alamo Heights Independent School District.

Prosecutors say that when the 15-year-old and her father, Ronnie Neal, 33, were taken into custody in the case last Wednesday, she had two fully loaded ammunition clips hidden in her socks and a gun under a motel room mattress.

When they were arrested, the two were in possession of some of Tilly's belongings. The pair also allegedly used Tilly's ATM card at several convenience stores, officials said.

The 15-year-old Judson High School girl is charged with delinquent conduct by reason of aggravated robbery.

Neal is charged with aggravated robbery. He has an extensive criminal record including convictions for auto theft, robbery, burglary and forgery.

Friends reported Diane Tilly missing late last Tuesday when she failed to deliver turkeys for a Thanksgiving luncheon at Robbins Academy. She is still missing. Investigators found a bullet hole in a couch cushion at Tilly's home, and found the teacher's burned-out car in Cibolo Creek.

The father and daughter's alleged role in the teacher's disappearance has left some of Tilly's students angry and baffled. Tilly was known for working hard to make sure her students graduated from the non-traditional school. Students say she would photograph new students in a cap and gown to remind them of the importance of graduation day.

"It's kind of like, when I didn't have my cup of coffee, she was my jump start," said one of Tilly's students, Joel Kainz.

The girl charged in the case, "doesn't really have anything to look forward to, considering she can be put in prison," Kainz said.

"I thought that was insane. I mean, bring your 15-year-old daughter into this?" said Courtney Touchette.

A judge ordered the teenage suspect to remain jailed Monday, citing the seriousness of the charges, her history of running away and a lack of adult supervision.

The girl lived with her grandmother in a house less than a mile from Tilly's home.