Yes, we are planning on getting another chicken and have reached out to a local farm animal store to get a bird, similarly low in aggression. She said we just need to keep checking back. We read these Polish are low in the pecking order and want to match that. My daughter would really like a silkie pullet. Thank you for that reminder!@New to Chicken I don't know that there is a real time line. Take the cue from her. If the hand feeding is going well and she is coming to you for treats, maybe sneak in a pet/stroke or two on her body while she's nibbling. From there, you can move to picking her up (football style) and holding her for only a couple minutes. Continue to gradually increase the hold time.
Another trick is to sit in the coop run and read or do something quiet...you just want her to get accustomed to you. At this point, you are not trying to touch/hold her. Sounds like your current pen doesn't allow for that and am not sure if your upcoming coop and run will.
Be aware though, not all chickens want or enjoy being handled. Thus, you may not be able to completely turn her into a lap chicken. Are you planning on getting her some friends. Chickens are social/flock animals and prefer to have other chickens around.