She takes really good closeups(won some awards at the fair) and wants to expand her interests in nature, but is hampered by her crappy cell phone camera. She is 15. What should I buy her? Telephoto bridge camera? SLR? Shitty Walmart camera??

Nikon d5200

Rated best entry level DSLR by... Pretty much everyone really...

You can get it on Amazon with a refurbished lens for about $550, that's actually cheaper than just the body...

link

I agree with this. Is you aren't looking to spend that much look into a D5100 which is simply the older version but will not hamper a beginners ability whatsoever.

Actually I've seen some very good photos take with phone cameras.  However, as the others have suggested, for her to improve her skills she'll need a entry level dslr.  Personally I like Canon but the Nikon are a close 2nd

No the camera has a CMOS sensor

Get a Sony nex  3n about 300 now and gives you an apsc sensor.

Is not really good in low light though. Not the best for action photo

spring the extra for the 5N, great low light performance and action.
Also, the Sony lens selection sucks, so invest in a quality adapter for whatever glass she has/wants.  I recommend Fotodiox F mount adapters but I am biased to Nikkor/Nikon glass.
Some examples, all with a NEX 5n and nikon glass and in some instances a macro extension.
NEX 5N, Nikkor 85, Macro







Nex 5n, 85mm hand held free lens

Nikkor 35mm, macro extension tube, handheld

Nikkor 35mm, macro extension tube, tripod mounted

And an action shot, hand held 85mm.






All the above photos did have post processing applied in lightroom, but the adjustments were minimal.
 
 
 
 
 
 

The Canon SL-1 18 megapixel, HD movie, touch screen, live view A super camera
SL-1

Get her a canon G15

http://www.bhphotovideo.com/c/product/889961-REG/Canon_PowerShot_G15_Digital_Camera.html

Let her learn the basics and then if she feels the need move to a Dslr.

This way you don't invest a ton of money into a camera and lenses if things don't pan out.  Also the G15 will make your daughter want to learn about photography in order to expand her skills.  With a Dslr it is far too easy to leave it in auto and get decent pictures ~90% of the time.  Also entry level dslr's have poor controls compared to the more expensive models which can be discouraging.

This is good advice.