Agreed. Lacey is dominating you, unfortunately. She IS being possessive, and that's not good for her, you, or anybody who tries to get between you two. You need to teach her that affection must be earned, not handed to her. You, as the benevolent leader, controls who gets what and when. If Sugar wants up and Lacey is growling, kick Lacey off the bed. If Lacey is on your leg and Marlin wants up and Lacey is growling, kick Lacey off. She's displaying dominance where she should not. You are not a resource but the controller of resources. And NILIF will help you nip that in the bud

For now, I would stop letting Lacey on the bed or in your lap *unless* she can earn it and she will get off on your command. It's imperative to teach "Off". If she won't get off on command, don't allow her on the bed just yet.