Amber Portwood has suffered many public humiliations over the course of her years in the spotlight.

But perhaps none of them stung quite as much as the embarrassment Amber endured at the hands of her own daughter this week.

On Tuesday's episode of Teen Mom 2, Leah Shirley roasted Amber in brutal fashion, revealing to the world that her stepmother Kristina has been more of a mom to her.

The humiliation began when Gary Shirley -- who continues to support Amber, despite the fact that she's done nothing to deserve it -- encouraged his daughter to work on her relationship with her mother.

"I'd tell you it's really important that, you know, you spend time with your mom," he told Leah.

“We don’t really have a bond like that," Leah responded.

That would have been humiliating enough for Amber, but it turns out Leah was just getting warmed up:

"Twelve years and she hasn’t really done anything," she continued.

"That's kind of been like Kristina's spot...All she did was give birth to me."

It was only a matter of time, of course, before Amber responded to all that hilarious and probably-accurate shade.

In what might be the lowest point in a life filled with low points (on second thought, that honor probably goes to the time Amber attacked Andrew Glennon with a machete while he was holding her baby) Amber went off on her own daughter in an Instagram Live this week.

“I try to invest time with Leah all the time,” Portwood said.

“It’s all I ever do," she added.

Amber went on to list everything she does for her child, and hilariously, it's just a list of the most bare minimum tasks performed by any mom.

"I try to invest time with Leah all the time, all the time. It's all I ever do," Amber shared.

"[Kristina] doesn't take care of my daughter. No, Gary does not clothe her, feeds her. Gary wouldn't have a job if it wasn't for me in the very beginning," she continued.

"[Leah] respects her because she brings her out to Starbucks, gets her nails done and spends over $1,000 of clothing on her. Hell, I'd respect her too. See, I wasn't raised that way. I was raised to not spoil my child."

Although Amber acted like she had been blindsided by Leah's criticism, it's not the first time that the relationship between mother and daughter has shown signs of strain.

Far from it, in fact.

"She's just getting older and she wants to know why and what happened back in the day and she wants to know certain things," Amber explained in a February interview.

"It's hard because it's hurtful to me when she feels possibly like she has more of a connection with somebody else than me because I'm not around as much as other people," Portwood continued.

"That sucks. I'm an hour way. It's hurtful, it really is. But I'm happy to watch my daughter become this strong queen."  

The good news is, Leah is only 12! Her mom has several years with which to build a more substantive relationship.

The bad news is, that would take work ... and this is Amber we're talking about.