What would you suggest as a way of decorating a foster child's room?

that's sounds gender neutral with is good, and your could always decorate it more once you get the child, like take them shopping for stuff they like for there room, you could let them pick a bedding, and some other room decor, so they feel that the room is there own. and in the future like several years down the line if you adopt them then you can re- paint.