Authorities say the killer had just had a miscarriage that she was trying to hide from her fianc.
Verna McClain, a registered nurse and mother of three was in court Thursday, charged with murder.
McClain is accused of waiting outside a pediatrician's office in a suburb of Houston, Tuesday, waiting for young mother Kala Golden and her newborn baby boy Keegan to emerge.
Police say Kala Golden was randomly selected, and that McClain had a miscarriage recently but never told her fianc.
Baby Keegan was was found unharmed a few hours after the shooting at McClain's sister's house.
He has since been reunited with family.
The district attorney has vowed to seek the death penalty, while her attorneys alluded to an obvious defense strategy.
"There is a lot of work that's going to have to be done to look into Ms McClain's mental state and see where that takes us," said defense attorney Stephen Jackson.
The judge ordered McClain be held through the weekend until a bond hearing Monday.