She just needs to realize that at bedtime she goes to sleep in her cage. You have to remember that she's still a very young baby bird, so she's going to have baby-like behavior.
Birds need 12 hours of sleep every night, so the best thing you can do is to talk to her gently and softly before bed, outside of her cage, telling her it's "bedtime", and then just put her in her cage, cover it, and let her be in there...if she cries a bit, and I know this is extremely difficult, but if she cries then you just have to let her cry until she finally falls asleep, because as already stated, if you keep going and waking her up or keeping her from falling asleep, she's not only going to not get enough sleep, but she's going to learn that "When I cry, they come get me", and then you're going to have a much larger all-around behavioral issue...
****VERY IMPORTANT*****
What I will warn you against....NEVER, EVER, EVER PUT YOUR BIRD IN YOUR BED WITH YOU AT NIGHT!!! I cannot tell you how many pet birds have been accidentally killed by people doing this, both purposely and accidentally, like they have their bird in their bed with them, watching TV, and they accidentally fall asleep and the bird goes under the covers...This happens all the time, every single day, with birds, bearded dragons, rodents/ferrets, rabbits, etc. Birds, especially little Green Cheeks, fall victim to this constantly...They typically suffocate underneath their person, as they tend to snuggle against their person and fall asleep, then their person moves in their sleep, and the bird suffocates against the mattress/sheets...it's terrible, not only does the person lose their bird, but they feel like they killed them...it's an awful, awful situation all the way around...