Optically active quantum defects are a leading platform for generating the many-photon entangled states needed for photonic quantum computing, quantum networks, and sensing. Generation rates can be increased if the defect spin can be coupled to quantum memories such as nuclear spins in the host material. Protocols that take advantage of this capability require a detailed quantitative understanding of electron-nuclear spin entanglement dynamics. I’ll discuss our recent progress in obtaining a better understanding of these dynamics and describe how the ability to control these dynamics can be used to improve the creation of many-photon entangled states.