Help! 30 min naps...😩

Help! My 3 month old has been on a streak for a few weeks of only taking thirty minute naps. We have a routine, she knows it’s nap time and will go to sleep with relatively little struggle or much rocking. But as soon as the thirty minute mark hits her eyes open wide. She doesn’t even quietly wake up, it’s all of a sudden. In the night her first stretch is 4ish hours and then she will wake up every two after that until it’s time to wake up. How can I get her to take longer naps without having to nurse her back to sleep or have her sleep on me?