Honey, i would be raising this, i am a manager in my office and would get my arse well and truly booted for behaviour like that...its not on...we have maternity buddies etc to keep you up to date when off on mat leave so she defo cant do this before you hav finished either.
go to her boss and get her told....its not on...folk like her make my blood boil, they shouldnt be managers if they cant behave properly, its a disgrace...

.bxox