ozzie, I couldn't work out if you know this already, so excuse me if you do - it is a very good thing that your daughter has caught rubella.
It will give her lifelong immunity which a vaccine does not guarantee.
The only danger of the very trivial disease rubella is the severe effect it can have when a pregnant woman catches it - the foetus is damaged.

Female children should be positively encouraged to catch rubella.

The effect of rubella on the foetus is no argument for vaccinating infants, in fact quite the contraray since the immunity which is conferred during childhood by its widespread occurrence is lost.