This is a birthday party for a four year old girl. It's hard to find betty boop items for a little girl. Get some red, pink or black balloons, hang them to the walls with streamers or ribbons, have some hellium balloons, have those placed all over the area of the party. Get some red and pink construction paper and cut out hearts, of all different sizes. Decorate the hearts with glue and glitter, attatch them to a red or pink ribbon, hang them on the ceiling and in the doorway. At a hobby store or at wal-mart you can find paper mache boxes of different shapes and sizes. Paint the boxes red or pink and paint a red or pink heart in the middle of the box, or if you know how to paint... paint betty boops face on it, and paint her name in the heart or if you paint her face, paint her name below the picture. The boxes can be party favors or decorations for the table. I had found some Betty Boop figures at a dollar store. I bought them all, I also bought some picture frames, and heart shaped wooden plaques. I painted the picture frames red, I wrote Betty Boop's name on the frame on one side and on the other I glued the Betty Boop figure to the frame.  You can add little decorations to the frame also, like glitter, foam hearts, gems, sequins, little pink or red pom poms, even some pretty feathers. If you can't find Betty Boop figures, then just decorate the frame with painted lips and paint her name on it. For the heart shaped plaque, I painted it red, glued the Betty Boop figure to the plaque, and painted her name below the figure, on the both sides of her name I glued pink foam hearts. It makes a good decoration or a party favor to take home.  The pinata bags, I got some white paper lunch bags. I got some sticker paper for my printer. I printed out Betty Boop pictures, and her dog pudgie onto the sticker paper. Then I put one sticker on each bag, and on the other side I put happy birthday. I did get all of the Betty Boop party supplies, plates, napkins ect.. I got red forks and spoons.  For the favor bags I found betty boop toy cell phones. The figures I found at the dollar store works good for the favor bags. Also add some hair clips for the girls, lip gloss, play makeup, little girl stuff. For the boys is much more harder to figure out because Betty Boop is more like a girl thing.. You can get some toy cell phones with like the betty boop ones but with spongebob, or some kind of boy theme, also some little bouncy balls, yoyo, little boy stuff.  Have every one wear red, black or pink. Or if you find some Betty Boop clothing then wear that. I know you can't really find small clothes with Betty Boop on it. So for the little girls have them wear a red dress, or a pink pokadot dress, or something that is similar to what betty boop wears, she has many different outfits! For the boys a plain red shirt with black jeans is good, or just all in black if possible.  For entertainment, rent a jumping balloon. Have Betty boop cartoons playing on T.V.(you can find these cartoon in stores that sell movies). Have the girls play dress up with some play makeup and hair clips, while the boys jump in the jumping balloon. The birthday cake.. you can find Betty Boop bendable figures on the internet for sale. Make a heart shaped cake with two or even three layers of different sizes, large cake on the bottom, medium cake ontop of the large, and a small cake ontop of the medium cake.  Frost the cake white, put the bendable figures where ever you want, and draw some hearts or lips made of frosting to the sides of the cake.  Or if you cant find the figures, a heart shaped cake will do fine, with the same heart and lips decorations, and some heart shaped sprinkles or some red sprinkles on the edges of the cake.