A woman seeking workplace accommodations on account of being pregnant has to provide a doctor's letter. But the letter has to do more than verify she is pregnant, coz being pregnant per se is not grounds for special accommodations coz it's not an inherently disabling condition. Women's experience of pregnancy and the limitations, if any, it brings varies widely. In each case, a doctor has to specify what this particular individual can do and cannot do.

https://www.eeoc.gov/laws/guidance/legal-rights-pregnant-workers-under-federal-law

Often, cases go awry coz of the way the physician has worded the letter:

https://well.blogs.nytimes.com/2015/07/08/doctors-notes-for-pregnant-employees-often-backfire-experts-warn/

If you want a laugh, look at these "recommended" letters from a website called "best medical forms" dot com:

Letter 1:

This letter is to confirm you that Mrs. [NAME] who is my patient & your employee is 25 weeks along with her pregnancy what must be in your knowledge. This is the stage that she needs to take the best care of her in every regard especially in concern with the physical & mental pressure as both the states can lead to catastrophic effects including preterm labor & many other complications related to the baby. So, it is advised that kindly do provide her with some relaxation in working hours so that she can keep up with a healthy pregnancy till the end.

Letter 2:

This is to certify that Miss [NAME] is my patient & I have been dealing with her case since the very start of her pregnancy. This is her 15th week into the new phase of her life & it is highly recommended that she must be provided with some relaxation at her workplace. She feels nauseated or sleepy and she must get some free time for that.

Since these are the most normal phenomenon that pregnancy brings in its beautiful but bony arms. She must be spared to get herself some food as many times as she craves for it as the baby needs food every now & then to grow properly inside the womb. The company must offer some flexibility to the mom-to-be who is going to bring the form of god in this sinned world.

Maybe the TIF in this case used a letter like one of those two and that's why things didnt' go as planned. I love the idea that pregnancy not only has arms, it has "beautiful but bony arms" LOL. But I guess it would account for the difficulty lifting.

https://www.bestmedicalforms.com/pregnancy-work-restriction-letters.html