I mean, he’s worked with the Kree before, there’s a chance he’s heard of her.
The universe is a big place though. It took him years to catch up to the Guardians and Tony (somehow he had heard of Tony). While Carol could have fought some of Thanos’s children at one point or another, it doesn’t mean that he went after her himself. It was kind of established at the end of AoU that he’d given up on letting others do his work, and that he was finally getting in on the legwork himself.
The events of Infinity War happened pretty fast. Probably over the course of what, 4 or 5 days? We don’t know how quickly Nova fell, but the Guardians were shocked about it. If Carol was in another corner of the galaxy, then it seems pretty realistic to believe that she didn’t know what was happening... until people started turning to ash around her.