I agree you should ask people beforehand, but being your 30th you only turn 30 once (well sometimes a few more times in some people ) and mothers day is every year so im sure that everyone will be able to be there for you.

Anyways mothers day when i was a kid was in the morning, we would spoil mum cook her breaky give her pressies then at lunch time she would say we were free to do what we want.