To be honest, I doubt you'll find a parents room in the first place. They will be quite rare.

In Malaysia, even though the Muslims are generally quite liberal, I personally don't think it will be a good idea to breast feed in public without being VERY discreet. I've done it but in the car with literally no skin showing.

The other thing you might find is, ppl will stare. Even the fact that you're Caucasian will attract some attention as it is. They might be a bit more subtle these days but you will be stared at. Mainly because they are 'amazed'/curious/admiring with no intention to insult. But you might find it a bit daunting.

I don't meant to despair you, it is possible but you will need to search for good spots. Sometimes I go into 'fancy' hotels and use their toilets as an alternative if I really need to.