Does she nap? If not, she needs to.
Do you have a bedtime routine?
If so... then PRIOR to the actual bedtime and routine... you need to "transition" her... to bedtime... instead of just all of a sudden.
So, say 1 hour BEFORE her bedtime... give a verbal head's-up... then, make everything dark and calm and quiet... let her do some quiet activity... like you read to her or watch a calm tv show. My son likes "Little Bear." Then, verbally cue her again "In 15 minutes, we go to bed... " and while she is winding down or before wind-down time... have her put on jammies and brush her teeth already. So then she can hang and kick back, before bed. Then, at bedtime, with her... go to her room. Let her arrange her bed etc., and make it all comfy. Keep the lights off or just turn only 1 light on. That is what I do. With both my kids: verbally cue them, transition them, wind-down with something calm, turn off things and make the room dark, if they want to watch Little Bear that's fine... by then they are already brushed teeth and in their jammies. Then they can 'relax' and watch Little Bear... and then, when it is done, that is the "cue" that it is bedtime. Then I walk them to their rooms... they arrange their beds... and get comfy... I talk a bit with them, keeping the lights OFF... and that's it.
I think... your child needs to be 'transitioned' to bed differently... now at her age. Not just all of a sudden, say bed time and then go to bed. Kids this age and older, need to "wind-down" first... THEN transition and then go to bed. Getting everything calm and boring prior. NO horseplay or any hyper activity before bed. Then they can't sleep and are too keyed up. Keep the house dark before bed...
all the best,
Susan