It seems to be that way with us too. There are always people telling me how little they are, and they always want to know their age. When I tell them they are shocked and 99% of them say that they thought they were still puppies lol. I always also get asked what breed they are - and if mine are brother and sister because their faces look similar I guess??
I think it's cute though that people seem to take such an interest in them....it's sweet!
P.S.- Your Trixie is soooo cute, no wonder people come up to you all the time!!