they probably wont get much bigger, sometimes having kids bnurse helps, but as you see her udder fill to capacity the bag will take up more room rather then the teats.
I have two two year olds that freshened last year as yearlings, who are a dream to milk. Perfect sized teats, for my hands. I had a third as well, but i sold her. Fantastic rear udder milked down to nothing has perfect sized teats. but for lack of a better foreudder she went to a dairy.