This is a biggie, so I feel I should write a fittingly large comment to go with it.
The idea of having a massive character of the younger female characters from The Simpsons - known to certain groups of Simpsons fans as the Playdudettes (after the fictional "Playdude" magazine mentioned occasionally in-show, and the real fan e-zine containing Simpsons hentai that was named after it) - came from the fact that a lot of the girls didn't have particularly great or common reference images.
So, from left to right, we have:
1) Maggie Simpson
2) Lisa Simpson. Her dress is the one she wore in THOH segment "The day the earth stood stupid", and her hair is the way she wore it briefly in "The president wore pearls".
3) Janey Powell
4) Allison Taylor ("Lisa's Rival", other eps)
5) Alex Whitney ("Lard of the Dance")
6) Francine Rhenquist ("Bye bye Nerdie")
7) Juliet ("Lisa the drama queen")
8) Sophie Krustofski ("Insane clown poppy")
9) Erin ("Summer of 4ft2")
10) Young Marge Bouvier ("The way we weren't")
13) Sherri and Terri's cousin ("The way we weren't")
14) Jessica Lovejoy ("Bart's girlfriend")
15) Samantha Stanky ("Bart's friend falls in love")
16) Greta Wolfcastle ("The Bart wants what it wants")
17) Mary Spuckler ("Apocalypse Cow")
18) Jenny ("The good, the bad, and the drugly")
19) Gina Vendetti ("The wandering juvie")
20) Laura Powers ("New kid on the block")
21) Darcy ("Little big girl")
22) Carrie ("Little girl in the big ten")
23) Tina ("Little girl in the big ten")
24) Jenda ("Future-drama")
25) Becky ("It's a mad, mad, mad, mad Marge")
26) Mindy Simmons ("The last temptation of Homer")
27) Manjula Nahasapeemapetilon (Apu's wife)
28) Marge Simpson
29) Ruther Powers ("Marge on the lam", others)
30) Amy Wong (yeah yeah, I know she's from Futurama, not the Simpsons....she was there to round the figure up to 30....
And that is that; the whole list - phew!
Many many thanks go to
for drawing this mammoth list of characters - in two parts no less, it was so big and took so long! THANK YOU TULIO!