E.O.
Try making bathtime fun. You can go to almost any large chain store and get things like bath crayons that wipe right off the wall (except grout if you have tiles) with the same washcloth you just got done washing her with. There are also tablets that change the water colors. Let her mix and match colors to make it her own...and let her take her time. If she's rushed she'll get stressed. If she's stressed every time she needs to take a bath she'll not want to go. As far as hair washing goes, sometimes you just have to make her, but before it gets to that try letting her lean back on her elbows and wet and rinse it herself. We call it "mermaid hair". You may have to do "dribbles" on the front while she's leaned back. Hope it works for you as well as it does for me (9 out of 10 baths). Just remember, if you get upset, she gets upset.