Here's a rundown from Wikipedia -- I have to say I don't remember this other than Lotta was well-liked. She was friends with Little Dot and Richie -- also Wikipedia mentioned Little Audrey who I also liked:
Far from being the "unpopular fat kid" stereotype represented in other popular media (such as her contemporary Tubby in Little Lulu) Lotta was depicted as friendly, kind-hearted and always ready to use her tremendous strength for what she deemed as good. She has her share of bullying, but any tormentors quickly regret provoking her wrath. In a sense, Lotta's storylines fulfill two very common childhood fantasies: the satisfaction of visceral desires (eating everything in sight) and freedom through physical power.
Who else remembers Little Audrey?