MIL expects us to skip my family vacation if SIL goes into labor

I’m so upset that my MIL keeps pressuring us to not go on a family vacation to the beach with my side because it is 3 weeks before my SILs due date. She has this vision that all of the siblings need to be at the hospital for the birth. Even though SIL has not said anything and I don’t believe would care if we met the baby a few days later. It’s also a 2 day drive away so even if we did leave early there is no guarantee we’d be there for the birth itself. Also for context I moved to allow my husband to live near his family and so this vacation is the one time every year I get with my whole family. It pisses me off that she would even suggest us missing it when I have made so many sacrifices for them to all live down the street from each other. Am I overreacting?