QLD Charging Daughter Extra for Milkshake - Legal under Australian Consumer Law?

[carer1]

When my daughter goes for a milkshake etc., she has to have soya milk due to an allergy. The shops she gets them from all charge 'extra' for soya milk on top of the standard price for a milkshake (or whatever) surely this is illegal under Australian Consumer Law? By rights she should get a milkshake with both ordinary and soya in it as they are charging her for both.

 

[Ponala]

No, not illegal. I imagine it costs them extra for soy and they pass that cost onto the consumer.