Gee kids are frustrating sometimes! It sounds to me like she needs lots more sleep. I have always found that when my boys are the most tired they are the hardest to get to sleep. If she is unsettled at night aswell then I would be trying to get her to have as much sleep as possible during the day, forget about routines until you can get her night sleep back on track and you know she isn't sleep deprived from that.
DS2 did this recently after we had GM staying and then he got sick. I have only just got him back sleeping through the night... he was just too tired to sleep soundly. It took a few days of putting him to bed any time he looked tired during the day and basically just trying to catch him up on all his missed sleep.