Just a suggestion. You may want to depict your adult Lisa as more of a size to Cecil, as she looks too small compared to him, almost like she was in her early teens, which is probably causing a lot of those troll responses. She looks too young compared to Cecil here, despite her obvious 'assets'. If you drew her closer to Cecil's size, she would look more 'adult' and acceptable to the general viewer. Hope this helps somewhat.
Good points. I actually didn't even notice how much smaller I'd made her until you brought it up. It's like when I look back at some of my earliest Sideshow Bob pics, and I can't believe how WEIRD he looks! Check out what I did to his beautiful nose in these pics: