I'm also due in a few weeks time but were admitted at The Matilda on Jan 13th due to false alarm I had that night. Yes, only 1 visitor and your own children (which is not a case for you) are allowed. You'll have to choose whether it's your husband or your mother that'll be with you in the delivery ward, and personally, I'd rather have my husband
This is my third pregnancy and I'll go to The Matilda again. I'm not bothered at all with their 1-visitor policies since friends' visits can be done after you've got home.
As for mother/mother-in-law, from my own experience, you'll need her more when you're back at home. During my previous two deliveries at The Matilda (before SARS), my mother and mother-in-law took turns visiting supposedly to care for me but I was in such good care and in a condition where I just wanted to spend time with my little one alone that they merely did nothing than sat there and watched TV.
It's only 3 days after all.
Hope you'll find this information useful enough. We might see each other in the hospital, don't we?