[CaveyCave]

riiight
In the drawing the mare's position with legs is a bit awkward and she would probably not be very balanced. I see you use circles, i personally don't use them as i think they make the horses face stumpy and fat. Also the face needs to be longer and ears bigger and with the hooves they usually 'dip in' before the hoof like this (bad angle sorry)
Also the torso is a bit wide and you don't really show the shoulder much.
Stallions and mares have different necks and you need to show that instead of drawing a line. In the Stallion neck you can see it is a bit like a C shape by the cheek bone and is more broad than the Mare neck which only has a small curve before going into more of a straighter line. The foal is okay but he/she needs longer legs, as foals have incredibly long legs, and we have the problem about the torso, ears and legs again. Also you could try the technique i used to do were i do a skelly kinda thing (shown on foal) though now i just draw them straight out XD

This is just the basics for now hope i helped

[RPFLightMyFire]

You did help, a lot, Thanks so much!!

[CaveyCave]

omg, im sorry, this red line isn't very good XD i'll re-do it

[RPFLightMyFire]

Please don't bother. I have improved a lot since I made that drawing so theres really no need to, thanks anyways though!(: