Los Angeles Superior Court Judge Sergio Tapia approved an extradition waiver for Couch on Tuesday.
She will be returned to Texas, where prosecutors have charged her with hindering the apprehension of a felon.
Her bail, which was set in Texas, is set at $1 million and must be paid in that state.
The mother and son were found in Mexico on December 28 after going missing a few weeks earlier.
Before he went to Mexico, Ethan Couch was on probation for killing four people in a drunken driving accident
in 2013, when he was 16. At the time, many were outraged that a judge sentenced him to probation instead of jail time, slamming his now-notorious "affluenza" defense -- that he was too rich and spoiled to understand the consequences of his actions.
In mid-December, a warrant was issued
for Couch, who's now 18 years old, to be taken into custody after his probation officer couldn't reach him. He appeared to have dropped off the radar after a video emerged that allegedly showed him at a party where alcohol was consumed.
Couch had been ordered to stay away from drugs and alcohol for the duration of his probation.
Tonya Couch returned to the United States on Thursday
. In video obtained by CNN, Couch can be seen in handcuffs with U.S. marshals at Los Angeles International Airport on her return from Mexico.
She has been in the custody of the Los Angeles Police Department since she landed.
Ethan Couch is still in Mexico; when he returns to the United States depends in large part on whether he decides to contest his deportation.
His lawyer, prominent Mexican attorney Fernando Benitez, told ABC News
that it may be "a couple of months" before Couch is deported if he chooses to fight the Mexican government.
Couch was about to be sent back to the United States last week before a Mexican judge granted the teen a temporary stay, which halted the deportation proceedings, according to Benitez.
In an interview with CNN, Benitez said he is not sure what Couch wants to do just yet. He said he's scheduled to meet with his client for the first time Tuesday and will pose the question to him then.
Benitez added that he thinks the Mexican government was trying to deport his client in order to avoid the lengthy process of extradition.
"We believe authorities are using the deportation -- which is an executive prerogative here in Mexico, whereby the executive branch can deport any foreigner without cause and without a trial whenever they see fit -- and they're using that in lieu of an extradition," Benitez said.
"To the extent of our knowledge, he has committed no crime at all in Mexico," Benitez said. He added that he is not sure if Couch had a tourist visa when he entered Mexico.