Ahhh mum and hats! lol.
Mums love a wedding hat but they are probably the worst thing to wear if they want to be seen in your photos because they often hide their faces and what you end up with is hat head! Even if you lift it up slightly for formal photos you still get a shadow over the face.
If your mum or MIL to be wants to wear one send her this link (sorry mums! but you’ll thank me after ;))
None of us want to see faces hidden so maybe try something smaller like a pretty head band or flowers?