Hi David.welcome to the forum.I, taking a guess you mean registering her death or funeral,I don't know why they can't be done at the weekend,I imagine registrars are doing weddings Saturdays and off Sundays.
I know when it happens you have the feeling of need to do something ,anything, and then sometimes life has been full pelt leading up too it and you don't know how or want to stop urgently doing things,but the time has come to take a deep breath and stop for a few hours..These places will be open tomorow.