Since when is Babs popular?
I like Babs because of her accent and the fact that her boyish personality is belied by girlish insecurity. For me personally, she's also got that "grown up in a kid's body" thing going on, where even though she's ten she might have three ex-husbands or something.
Some of this could be said for Trixie too. She's a loudmouth with an insecure or sensitive side occasionally bubbling up. I think the conflict makes it more interesting to see what they would do in a story than, say, Trenderhoof.