My employer is happy to let me take my annual leave on full pay before I start maternity leave. So I will start my accrued annual leave of 3 weeks and then immediately following that I start maternity leave.
I did this with DD as well.
This is all part of our enterprise bargaining agreement but if you work somewhere that doesn't have that I'm not sure.
Though I would think they should have to pay you out if you're not taking it but with the recent IR changes I'm not sure.
sorry that's not much help!