HOUSTON -- A Katy teen convicted of murder in an accident that killed a teacher will spend six months behind bars before her 10-year probation sentence begins, KPRC Local 2 reported Monday.

Breeana Zipf, 18, was sentenced to 10 years probation on Friday after a jury found her guilty of murder in an accident that killed Gwendolyn Davey, a kindergarten teacher at Chambers Elementary School. She had been with the Alief Independent School District for 14 years and was engaged to be married.

However, the judge added 180 days in jail to Zipf's sentence on Monday. She began the sentence immediately.

Prosecutors said Zipf was speeding on Sun Glen Boulevard in west Harris County when she went up over a curb and hit Davey, who was walking her dog, in July 2004.

Zipf claimed she blacked out and did not remember hitting and killing Davey.