I'm not sure where you're from, but in Canada, there's a chain boutique called Town Shoes, and I saw some shoes that were manufactured by the Barbie line a little while ago. The one I saw was metallic rose pink heels with a bow on it, soooo cute!
If you or your sister is a DIY person, you can consider buying a pair of white dye-able shoes, either pin or glue a bow or rosebud at any preferred position you like on the shoes, and then get them dyed as either ivory or light rose pink.