Later in 2020, Ms. Lavelle also complained to the board, describing how she had been traumatized by her daughter’s tongue-tie release.

The lactation board, which reports its disciplinary decisions, has not taken action against Ms. Henstrom. A spokeswoman for the board, Susan Brayshaw, declined to comment on the complaints, citing a policy of confidentiality. “Some complaints take significantly longer than others due to the nature of the allegations and related investigations,” she said.

Since 2002, the board has revoked the certifications of only three lactation consultants.

Ms. Lavelle also filed a complaint against Dr. Zink with the Idaho board of dentistry. The board collected medical records and statements from Ms. Lavelle and Dr. Zink. Dr. Zink told the board that June’s procedure was “uneventful” but that an extremely small percentage of patients do not respond well to the procedure. He said none of his hundreds of other tongue-tie patients had previously complained.

The board’s executive director informed Ms. Lavelle via email that the group “didn’t feel that further investigation was warranted.” It found that Dr. Zink was not at fault.

Late last year, Ms. Henstrom recommended tongue, lip and cheek tie releases for an infant named Vivi. Sitting in Dr. Zink’s waiting room a few days later, Vivi’s mother, Aubrey Nobili, could hear her baby’s screams over the muffling hum of a noise machine.

When Ms. Henstrom brought Vivi back into the room, the wailing infant couldn’t catch her breath. Ms. Nobili pulled her daughter close and smelled charred flesh.

Vivi never breastfed again.

Six months later, a specialist at St. Luke’s assessed Vivi because she was having difficulty swallowing and would sometimes choke while drinking from a bottle. The specialist wrote in her medical records afterward that the problems were “likely due to” the laser surgery.

Ms. Nobili is a stay-at-home mother, and her husband, Ryan, works at Costco. They have four other young children. They said they ran up more than $5,000 in credit card debt paying for Vivi’s feeding therapies.

She turned 1 in November. Her family decorated their home with red and pink balloons and dressed her up as a strawberry.

Only one thing was missing: a birthday cake. Vivi still can’t eat solid food.