Police were called to a house on Millen Road near Barton Street around 7:30 a.m.
According to police, the woman was in her yard watering flowers when she was approached from behind by someone who tried to steal a necklace she was wearing.
The woman fended off her attacker by “biting, slapping and screaming at the suspect,” said police.
The attacker fled without the necklace, and without his bike, too.
Police describe the suspect as a 14-15 year-old male.