We've bought a house, which we are renovating ( new wiring, plumbing, kitchen,bathroom, doors, skirtings, windows, the lot). The house itself is a bland 1960's, not especially pretty, but detached and has good room sizes and a decent garden. I really fancy having an Art Deco 1930's style bathroom, with fancy Art Deco mirror, wall lights and beautiful tiles. Husband likes this too as he likes the large flat sinks from that time. Will it look odd to have different rooms in different styles? The kitchen and dining room, and main living space will be a nice mixture of shaker and mid century furniture, and my daughters bedroom will probably be country cottage style cos that's what she likes.
I think that sounds fine. The most important thing in my view is to make all your communal day to day living space flow - which it sounds like you're doing.
Having a slightly flamboyant bathroom sounds great to me - it will make you smile every day. And if your daughter wants country cottage then why not. It's not like you'll be entertaining guests in her bedroom. You can help things gel by picking out similar colours or accessories. Eg I have prints in black frames in both our living areas, hall and our bedroom - I feel this helps pull the house together (sounds a bit wanky saying that out loud!). If you want to rein it in a bit then focus on letting her pick out lovely duvet covers and stuff for her walls.
Ds is asking for black walls with Storm Troopers all over them....hmmm, not sure we will go that far! I feel a search for Star Wars wall stickers coming on. I plan to beautify the outside of the house too, but that will require a lot of careful thought, to make it look like its always been like that.