Hello and welcome to BW forums
Looks like you've made a fabulous start to EASY
It's quite normal for it to take a full 20 mins to go to sleep although over time this can change and reduce with some LOs. I could set a clock by that 20 mins with my DS in the early days but later, when he was sleeping independently, he preferred a very short wind down and to just get into his bed, maybe 5 mins, just a quick nappy change and 1 song then down and leave him. Of course through tricky times, routine changes and teething etc it can also take a lot longer than 20 mins to properly settle a LO even if they are an independent sleeper - that's just how it goes.
For now then the 20 mins sounds spot on - brilliant!
Depending what the crying is like when she is being held at your shoulder, if it is low level she might be trying to self sooth, a mantra cry, this is the sort of cry where you can put her down and shush/pat in the cot. Or she might now realise she is very comfortable for sleeping in her cot and is asking to be put down, although may still need help to fall to sleep. A little experimentation might be needed. If she is crying hard though it could be something bothering her, UT (under tired) or OT (over tired) although it sounds like you are acting on her sleepy cues well.
I found with my DS that he needed the view for his "seven mile stare" not to change, he would focus on the same thing (strong tonal contrast) for every sleep and if that view changed he was restless. For this reason I realised I needed him to be down in his bed for the seven mile stare so that firstly he could begin to nod and see the same view and secondly if he opened his eyes during the transition from one cycle to the next he still saw the same view and could either stare or nod or shut his eyes and go back to sleep again. Getting LO down into the cot as soon as you can and continuing shush/pat there is the aim, but if she is upset of course you pick up and comfort in arms and all the way to sleep if necessary.
I hope this helps some.