Dolly Bureau books have a few patterns for Momoko, but I think this is one is my favorite. The set is a jacket, skirt, and blouse. It can be found in volume 1 of the Dolly Bureau series. The Momoko pictured is Beach Rodeo. She is also wearing glasses by Randall Craig. The book is still in print and you can make the outfit too! See below for more details.
The most recent installment of Dolly Bureau volume 3 focuses on tiny dolls, but some of the crafts and sewing patterns can be used for dolls of multiple sizes. The picture below is a drafting dress pattern that would use a combination of knitted and tulle/lace fabrics. Dream High Studio's Lulu is pictured. She's so tiny!