WOW, thats quite a dilemma. Well i don't really know where she could be you better check EVERYWHERE though she could be up under the seats or inbetween seats or anywhere. Hopefully shes okay. Maybe you shouldve brought a secure carrying case if you were taking her out with you. Although why would you take her out with you to eat with someone who you weren't sure if they liked snakes or not??? Snakes aren't really pets that should be brought out with you, maybe you should get a little dog or something?