You need to build her top line, and with her being young she needs muscle,  a good quality protien feed along with lunging regularly will help to build up both.  She has a fairly upright shoulder, so I wouldnt advise much in the way of jumping as she will feel the concussion more from landing, very pretty face.  Love to see the pics when she has matured. 

Sharon

She is a cute mare! Im not a pro at critique, however with work I am sure she can have a topline not as straight, I don't know what you plan on doing with her and what the critique is for (overall conformation, performance), but I am sure you will have alot of fun with her. I will also say that I second the halter with a bit tied to it NOT safe at all. Buy a bridle.

*edited to add* I took a better look at her pictures and definatly get a farrier out to look at the right front hoof. She definatly needs a trim the toe is extremly long.

She is a very cute.

She is long in the back, making her muscling that much more important.  She has a pretty straight shoudler, she's downill and toed out in back.  None of these are horrible faults either.  With a few more years on her and some muscle she could do about anything.  I wouldn't pick her for dressage, we like 'em uphill but other than that she looks like a nice little mare.

if you back her up this will halp build muscle in her hind end to.