Hello and welcome to BW forums
It could well be that she just doesn't like to sit! Mine liked a super short wind down, when I tried the longer WD with all the ritual aspect for a few days he blew a fuse. He liked to play right up to nap time then prob 3 mins max between playing and sleep, I took him into his room, sang a verse of a song and put him down (I couldn't do any of the curtain shutting etc). If he appeared to need it I sang 2 verses but there were times he was pushing away form me before the first verse was finished, to show me he wanted to get to bed.
Whilst she may seem very tired because she starts screaming if you delay her bed by doing sitting it also looks like she could do with a longer A time to be fully tired and more able to transition to the next sleep cycle (with help initially), it could be a relatively simple case of not starting the WD so early, so the A is longer, but once WD starts she wants it short and to the point.
A times at this age are around 1hr 30 to 1hr 45
Average A times- BOOKMARK ME! Was she awake from 9am to 12pm? That seems a very long time to go without a nap for this age.
At this age LOs are more alert and sleep cues can become confusing, a yawn can indicate the need for a change of activity, scene or toy (ie it is boredom) so move rooms or change what you do with her and extend the A for a later nap, then I suggest being in the room to help transition at 40 min so that she doesn't fully wake but has help with you soothing her. Are you familiar with W2S, Wake to Sleep? It looks like you are already using this method to try to extend the nap so you can continue with that.
hope this helps