How to manage baby #2 dropping to one nap when #1 has 12:30 school pick up?

My 4.5 year old gets picked up from school at 12:30. We have to leave at 12:15. My 13 mo/o is about to drop her second nap. She’s was doing 9:30am and 3:30pm which worked great for us. The last few days she hasn’t gone down in the AM until 11 which just doesn’t give her enough time to sleep. I’ve had to wake her up for school pick up. What has worked for you? Thanks!