I did once or twice lie next to her because I am just SO tired which I know is a no-no.
Why is it a no-no? I always wonder why it is said that meeting the needs of family members at the moment is a no-no?
At 2yo they have a greater sense of the world & often the night wakings are driven by needs for comfort and validation. They know more about the world & the tiniest fear that they have been left alone is greater at night. The calling out & the screaming are for validation. It could have been some simple moment where she lost sight of you & got frightened or a time you went out when she was sleeping & while someone else was there for her it sent her into a fear response & that comes back... some children ARE more sensitive to emotions & while their siblings don't react that way they do, so as a parent what works for one child can be different for another.
Honestly, the best way forward is to meet her at her needs. Sit beside the bed until she falls asleep & after a week or so, try & move a bit further away & work on it as a long-term goal. I *know* in the evening it feels like it eats into the *me* time, but the long-term trust is what prevents her from making the needs met in another way