Sunday must have been a difficult day for Anna Duggar. The mother of four brought her children and accompanied her in-laws first to their 11 a.m. church service in Arkansas, then to her cousin-in-law Amy's nearby wedding to Dillon King that evening. Both events had heavy connections to Anna. WATCH: Duggar Family Bracing for More Josh Bombshells First, at Cross Church, Pastor Jeff Crawford gave his congregation what one eyewitness described as a "fiery" sermon about pornography, which Crawford called a "secret sin.” Anna's husband, Josh Duggar, confessed in a statement released last month to being unfaithful to his wife and becoming addicted to “viewing pornography on the Internet,” a revelation that has since been removed. Anna was in the crowd listening as Crawford said, "I know there are some folks in here today -- pornography is a deal in your life." Josh, who is seemingly still in treatment for sex addiction, wasn't there Sunday, leaving Anna to look after their young children on her own, albeit with help from extended family. She wore a blue shirt and a long khaki-colored skirt, and greeted fellow churchgoers with a smile. Anna even posed for a family photo up front after the service. The Duggars were the last to leave the church, piling into a van and heading back in the direction of their home in Tontitown. ETONLINE As for rumors that Anna is holed up in a mountain home, a source close to the family tells ET that's likely not the case right now. "I don't know for sure because the family is staying so quiet," the source says. "But she's probably with Jim Bob and Michelle." Anna's in-laws publicly declared their support for her as Josh entered treatment. WATCH: Could Anna Duggar Ever Leave Josh After Cheating Admission? Anna still seemed upbeat as guests gathered for Amy Duggar's wedding at Horton Farms Sunday evening. She chatted with family and took a seat with them, but as the ceremony began, her happy energy seemed to fade. The man who married Amy and Dillon told the pair to be "open, honest and faithful" in marriage. He advised that they go "all in" for both each other and Jesus. He told the newlyweds marriage is about being "only with each other for the rest of your lives." "Anna definitely looked somber during the ceremony," an eyewitness tells ET. "She was watching and listening, and she just looked kind of sad." The former reality star ducked out quickly after -- she wasn't seen at the reception. "Bless her heart," a source close to the Duggar family says. "She tried to put a smile on, but what it must have been like for her to be at a wedding…" According to sources, Josh is in a treatment center in Rockford, Illinois. Anna has not spoken publicly since his cheating scandal broke.

As Anna Duggar sticks by her husband, Josh Duggar, despite his confirmed infidelities and scandals, people around the country are speaking out against the blind support from the 19 Kids and Counting star's wife.

Suburban Atlanta mom Jessia Krammes Kirlkland penned a lengthy open letter on Facebook on August 20 that has gone viral after she called out Anna's situation and explained that she will teach her own two daughters "to think they breathe fire."

NEWS: EXCLUSIVE: Josh and Anna Duggar Hide Out in Mountain Home as Family Avoids Public Eye

In the post, Kirkland asks that more people talk about Anna, as she is in the "worst position she could possibly be in right now" because she's following the rules that had been laid out for her.

"Anna Duggar was crippled by her parents by receiving no education, having no work experience (or life experience, for that matter) and then was shackled to this loser because his family was famous in their religious circle," Kirkland writes. "Anna Duggar was taught that her sole purpose in life, the most meaningful thing she could do, was to be chaste and proper, a devout wife, and a mother."

Kirkland goes on to explain that she understands where the plight is coming from, as Anna's religious environment restricts divorce. "Her beliefs, the very thing she would turn to for comfort in this kind of crisis, are the VERY REASON she is in this predicament in the first place," the author continues. "How can she reconcile this? Her parents have utterly, utterly failed her. Think of this: somewhere, Anna Duggar is sitting in prayer, praying not for the strength to get out and stand on her own, but for the strength to stand by this man she is unfortunately married to. To lower herself so that he may rise up on her back."

The note ends with both a battle cry and plea to parents. "WE MUST DO BETTER BY OUR DAUGHTERS," Kirkland writes. "Boys, men, are born with power. Girls have to command it for themselves... We HAVE to teach our daughters that they are not beholden to men like this. That they don't have to marry a man their father deems "acceptable" and then stay married to that man long, long after he proved himself UNACCEPTABLE."

"Educate them. Empower them," she adds. "Give them the tools they need to survive, on their own if they must. Josh Duggar should be cowering in fear of Anna Duggar right now. Cowering. He isn't, but he should be… I wish someone had ever, just once, told Anna she was capable of this. That she knew she is."

WATCH: Anna's Brother Slams Josh: 'I Won't Stop Trying to Get That Pig Out of Our Family'

The letter, which as of Tuesday afternoon had over 433,000 likes and 239,000 shares, spurred its own hashtag, #BreatheFire, a tattoo design from a Des Moines artist and, least surprising, a Daenerys-inspired meme.

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Kirkland spoke with local Atlanta news station 11alive on Tuesday, saying the letter was not meant to be an attack on Christianity, but rather a way to speak out against the idea that "you need to be a certain way in order to meet a standard your community demands of you."

"I hope the message stands alone," she told 11alive's Julie Wolfe. "I want girls to know their worth and accept nothing less."