Alli Sims BSPEARSALLI120707_04.jpg Alli Sims has always been a loyal friend to Britney Spears... so how come she pulled a last-minute U-turn when she went to visit her friend last night?

Our photographers saw Alli driving up to the Summit last night around 7:45 - but right before she was about to come inside the gates, she turned around and headed home!

Could this be Jamie's conservatorship order in action? After all, the second power granted to him by the court in the written order allows him to "restrict and limit visitors"!

Do you think Jamie just wanted his daughter to get some rest? Or has Alli fallen out of Jamie's favor?