Socialised feral kitten scared to go outside

Hi everyone, looking for some advice. I have a 5 month kitten who was a feral up until 11 weeks. She is now a socialised queen, and is super trusting. I have 2 other older cats who go outside during the day and come in for the evenings and night. (We live on a farm in the middle of no where so I feel happy to let my cats out without risk of being run over, etc.) I have started to take my kitten outside on a leash to acclimatise her to the outside, as she loves bird watching and sunbathing by the front door. We have been doing this for two weeks on a daily basis, and she absolutely HATES the outside. She shakes in fear and screams, running herself back indoors. We have seen no progress in the two weeks. Is this normal for anyone else? Is it worth continuing or is this her way of saying she wants to be a homebody? I wondered if it had anything to do with her feral past, or if I'm reaching.