Im late to this party but well, here goes.
Talk to then, be nice, tell them how pretty they are and pet them when they come close to you. Having food is always a benefit.
Mine will come up to me, Ill reach down and they'll submit and Ill give them a good ruffling and tail tug and they love it. I can reach down and pet them a bit, I will pick them up and talk to them when I scold them. They give me the look of Ok Hooman then go right back to what they were doing when I picked them up.
it takes time, they need to get used to you. Some birds NEVER will let you do this. I have one that is very skittish, and even after watching the others get hand fed berries and stuff, still rarely comes up to me. It's just the way some are. I have others that the untrained eye would say is attacking me when i come out first thing in the morning. She's not attacking she's wanting to see what I brought for her. She will literally jump straight up trying to get a look in my hands, it's pretty funny.
On the lap, sometimes they will sit on my lap and let me pet them a few minutes then hop off the moment something catches their attention. Other times Ill pick up two at once, they will literally be right next to each other and ill grab them one hand on each side with their other sides against each other and pick up the pair and I will give them like mini airplane rides saying oh look it's chickenzilla destroying jacksonville !! Yah, they tolerate me sometimes...
How long does it take? Hard to say, Big red I got at about a year and a half old and she took to me right away, though her original owner just had her in a huge pen with about 30 others and did not spend any 'family time' with them. the other 3 I got as probably 8 weeks old, and two of them it only took about a week for the to ping on me and maybe 3 weeks to be feathered leg magnets. The other one, never did.
Don't give up on them, don't rush it and above all, don't feel bad if you get one or two who won't warm up to you, after all they are wimmin and you know how finiky those creatures are!!
PS - Jealousy works wonders for smarter birds like Cockatoos, but chickens are pretty indifferent Ive seen, except maybe a rooster but that's a different .. oh wait.. the cockatoo... never mind... Trying jealousy as a tool of behavior modification, may get your ass beat, by SEVERAL species'
Aaron