Lydia hopes Alpha came to extract her from Hilltop out of motherly love.
Perhaps there was a little of that going on, but its not the Whisperer way.
Alpha begins to question her daughter about what she learned.

Credit: Gene Page/AMC
The boy gives up that hes from Hilltop and he came for Lydia.
Alpha considers the Whisperers to be animals.
They live like animals.
She had already mentioned to Daryl, they care for babies in the wild like animals.
She tells Lydia now she likes animals because they dont lie.
When they reach the Whisperers camp, more of their daily lives are unmasked.
For one, theres a whole lot more than suggested.
Their faces are all smeared with dirt and rot, presumably to further mask their scent.
Henry is tied up to a tree in the center, watching all of this play out.
Alpha says it was worth it since now they know where Hilltop is and how much supplies they have.
People follow her, she adds, by choice, because she makes them strong.
So the man does, but Alpha turns the tables.
As Beta holds him at knifepoint, she faces the woman.
The woman doesnt want to fight, but Alpha says its too late before decapitating her.
Alpha hands her head to the man and kills him too when he starts whimpering.
After all, Crying is weak.
This is, obviously, an extreme.
Yet, Michonne is chastised at Alexandria for pulling similar political tactics.
Though unintentionally, Michonne is also using fear to secure political power.
Now everything is a security concern, he says.
Hes changed, he argues, and wants to pass along some wisdom leader to former leader.
He, too, notes that Michonne is taking dominion over Alexandria, but she doesnt listen.
She confronts Judith at home later and learns shes been speaking with Negan.
But back to the Whisperers…
Alpha and Beta reconvene in her private quarters.
In the dead of night, Beta brings Henry forth before Alpha and Lydia.
Alpha commands Lydia to kill Henry or Beta will kill them both.
In Whisperers speak, walkers are called guardians.
So all four of them abscond.
If Dog dies, I say we riot.