The "Sister Wives" cast member recalled the doctor asking to speak with her in his office after a two-hour appointment.
"It usually takes about 45 minutes, but the doctor just kept looking and looking,” the 23-year-old told People magazine. “I was stressing out the whole time.”
He then told her that he couldn't find all her daughter's fingers.
At that time, the unborn baby was diagnosed with oligodactyly -- a congenital condition where all five fingers do not develop on one hand.
“There were lots of emotions,” she says, “but I was also relieved because there could have been a whole lot more wrong.”
She and her husband, Caleb Brush, welcomed Evangalynn Kodi on Aug. 20. It was then determined she was born without a thumb and a toe, two fingers were fused together, one of her legs did not develop a fibula (calf bone) and she had a bowed tibia (shinbone).
“We were shocked,” Brown Brush said. "I was just sitting there trying to comprehend what’s going on, having just had a baby as they are bringing in all these specialists. I was freaking out.”
They are also parents to 2-year-old son Axel James, who does not have any complications.
The final diagnosis for Evangalynn was fibular aplasia, tibial campomelia and oligosyndactyly (FATCO) syndrome, which is a very rare genetic disorder that affects bone growth in the uterus.
"We were hesitant to share Evie’s condition publicly for fear that our infant daughter would become the target of mean jokes and cyberbullying," Brown Brush wrote on social media.
"That said, we felt not being open would be even worse and make Evie feel ashamed for something that makes her all the more special in our eyes... As far as we have been told, with fewer than 10 recorded cases of her specific findings, it’s unclear what causes the condition."
"She is healthy in every other way aside from the missing bones. As a family, we have decided to be open as we walk through this journey. We want Evie to always feel pride in who she is, and all that God gave her!" the proud mother concluded.
The family will wait until Evie is 1 year old to determine the next course of action, including considering surgery or amputation.