Hi, any Dis Campers

Starting to get DD organized for her adventure camp next month. She needs a sleeping bag that is lightweight and stuffable, suitable for warm weather camping - temps will be in the 70s at the lowest. All I've seen in local stores are bags rated for super cold (which seems odd, since we live at the beach

), and our old scouting bags seem huge for a tween girl to be managing on her own. She will be literally camping, not in a bunk, and will move camp several times.
Do you have a favorite sleeping bag? Any suggestions for good websites to find one? Or is there an alternative I'm overlooking? Surely this camping item has improved in the 30 + years since I've needed one?
TIA
Having once worked in a high-end camping store, this is a topic I know well.
I personally have a Coleman semi-mummy with polyester durafill. It's rated 0 degrees, but in the summer I sleep with it unzipped and find it comfortable. It was my 15th birthday present, which makes it 29 years old. That bag spent three summers working at camp, it's camped on a driving trip cross country, it was important when I worked an Outward Bound type job in college, and it has been on countless scout trips. I know it cost $90 back then, but I have used it sooooo much and it still looks new. Or at least very, very good. It has never, ever left me cold. This particular bag is best for car camping, as it does not pack super-small. A good bag is an investment.
Here are some things you ought to know when choosing a sleeping bag:
Shape
If weight isn't a concern, or if you want the option of zipping two bags together, a rectangle is fine. These bags are also cheapest. Be careful in choosing a rectangle bag; many of them are flimsy and won't hold up to repeated use. It's not that the shape is bad; it's just that the cheaper manufactuers use this shape because it's easier for them.
Mummies are warmer for the winter (less space for your body heat to fill).
Semi-mummies are a mid-way point -- a little more space for comfort, a little heavier to pack.
Mummies and semi-mummies tend to have draw-string hoods, which allow you to close up the wide shoulder opening, retaining heat in the cold weather.
Bags come in short, average, and tall. Choose a bag that fits her size; her body heat'll fill it most efficiently, and it won't be wasted weight.
Filling
Down packs down to almost nothing and is super-warm. It is also super-expensive, and if it gets wet it's worthless. Down must be professionally cleaned. When you lie on down, it completely compresses; this means you have literally no fluff underneath you, and a sleeping pad is essential.
Synthetic fibers (polyester, durafill, holofill, etc.) do not compress into tiny packages like down. They can, however, be thrown right into the washing machine (but not the dryer). If a synthetic bag is wet, it still retains some of its ability to keep you warm. Synthetic bags are also considerably more affordable than down bags.
Temperature ratings
A temperature rating refers to how comfortable an average-sized man would be in this bag. It assumes that he is sleeping in a tent and has a sleeping pad (sleep pads not only add comfort, they also insulate the sleeper from the cold ground). Women tend to like a slightly warmer bag than do men (smaller body = less body heat expended, less body heat to trap in the bag).
Nice details in a bag:
Double zipper -- choose a zipper that can be opened from the bottom or the top. This allows you to open up the bottom so your feet aren't over-heated, and it allows you to walk around camp IN your sleeping bag.
Baffle to cover the zipper -- this is a piece of cloth sewn in place to prevent you from touching the cold zipper during the nightime. It also prevents cold from seeping in through the zipper's teeth.
Double layer construction -- you definitely want a bag that is made of two layers of material, each quilted separately. Why? Every place the needle goes through the material, there's a tiny hole; that tiny hole can let in cold. If you have two layers of material, the holes won't line up. Also, the idea is that warm air is trapped between layers -- and more layers = more warmth.
Eyeglass /ipod pocket -- very convenient.
Soft inner lining material -- be sure it's a good quality material that'll hold up over time. My dear old bag shows more wear on the inside than anywhere else.
Ripstop nylon outer material -- a good bag won't show snags and pulls if it's treated carefully. Of course, you're never going to put it straight on the ground; you'll always use a sleep pad and/or a tarp, even if you're tent-less.
Extra stuffing in the foot of the bag -- obviously, for extra warmth in the foot area.
Care of a good bag:
Never, never roll a sleeping bag. Instead, stuff it into your stuff bag. Rolling puts creases in the same spots repeatedly, and over time this deteriorates the bag, shortening its lifespan.
After a trip, always air out the bag before storing it.
At home, remove it from its small bag and store it hanging up if possible; many good-quality bags have loops on the foot for this purpose. If that's not possible, at least store it in a large box or open plastic tub. The idea is to allow the fibers to "stretch out" and breathe.
Wash it on gentle cycle in a large machine (only when needed -- try not to wash it after every single use) and let it air dry.
Ebay is a good place to buy sleeping bags. Failing that, try Campmor -- it's online.
Want me to talk about boots?