i want you to know i strained my brain to think of the title of the books i have! i knew i would forget to check at school tomorrow and didn't want to post to tell you i had a cool resource and then not follow through.
SO.... Cartesian Cartoons and Cartesion Cartoons Holidays are great. They may be a bit challenging for 4th grade--but there are some simplistic ones. there are pics of: frog, apple, bunny, etc--and some cute ones for holidays--but a couple "weird" ones--like a pregnant tired lady and 3 little kids for mother's day. huh?
anyway, you can get both at Amazon--about $20 for both.