I don't know anything about ArtSci but I'm in 2nd year and live on residence now and I also did in first year so I can answer res/meal plan questions.
Non-communal washrooms in Hedden too. There are a bunch of washrooms on the floor, and they're all rooms with a lock. Each one has a shower, toliet and sink. You share them with others on your floor but there are lots of them. They aren't public washrooms like most of the other residences have.
Whidden first floor also has the same type of washrooms as Hedden for some reason.
Les Prince has personal washrooms in your room.
The non-traditional residences like Keyes and Bates also have non-communal washrooms.
That said you said that you needed to be in an all girls residence. There's only one all girls residence and that's Wallingford and as far as I know they have the public washrooms.
The public washrooms are really not that bad though. The showers take a little getting used to but the washrooms get cleaned every day and stuff so it's okay.
As for healthy options on campus there are actually quite a few options. Yeah there's a lot of places that have the more unhealthy options like fries, burgers and pizza but there are other options too.
In Commons they have a salad and fruit bar with lots of selection, they also have Your Healthy Choice. YHC has two stations, one with custom pasta/stirfry where you can get either pasta or rice noodles with lots of veggies, and they also have chicken. The other station has different healthy meal selections each day that the chef cook's up for you. For example they have pitas with different stuff in them, sometimes they have steak and other different types of specials. Their meals come with options like salad and rice so it's healthier than having the burger and fries.
In Commons definitely stay away from Sizzles.
Commons also has Pillers, the place with different sandwhiches and wraps and they have tons of veggie options to put on them. There is also a Pillers in the student centre.
In the student centre at Creation X they've also added some healthy menu options this year. For example the turkey burger with cranberry which I tried earlier this year, it was good.
The student centre also has Japan Teriakyi Experience. I don't know if you've ever heard of it, but this is it: http://www.teriyakiexperienc e.com/
Bridges as mentioned is a vegetarian resturant that is pretty healthy. Don't worry if you're not a vegetarian either, the food is great. I'm not a vegetarian but this definitely my favourite place to eat. It's a little more expensive but it's worth it. They have a ton of different options on their menu, as well as a daily special that always changing. They have a pasta bar as well with a ton of selections to choose from, many different types of veggies, as well as beans and tofu. Whole wheat pasta is also an option. If you're not a vegetarian and you're skeptical about it don't be, you won't even miss meat. Their veggie chili is wonderful, as are their soy chicken options. I've tried a bunch of different things on the menu and enjoyed them all. All their bread is whole wheat multigrain but it tastes so good and you'll feel better eating healthy carbs. They also have vegan options.
Bistro is a good resturant but I they have so much on their menu so I can't go into detail about what they have there that is healthy. The food is good quality though, like the kind you'd get at a regular resturant imo.
They also made lots of different types of fruit smoothies at different locations around campus that are good.
I wouldn't say the Meal Plan has mostly unhealthy options, I would say it all depends on the choices you make. Obviously choosing fries or pizza every time you go to get a meal is not a healthy choice.
I personally try to make healthy choices, and also keep fruit and healthy snacks and drinks in my room.