Not just Tilly. We are in Norfolk and lambed in March/April and had a couple of cases. The worst one was a ewe who's lamb was dead. Huge size, arched back and presented with it's back to the rear, head and legs forward. Had to get the vet and the lamb came out in bits.
Also someone else a few minutes away who lambed earlier with a reported 40% loss.
Rams in now and fingers crossed for the spring.