Welcome to the forum! I like your paint horse's colouring. And, I do agree she could use a little more muscle and bulk. Is she a younger horse as with some fitness and time she can fill out a little more for sure. Nice mare!
I'm by no means a conformation expert, but I'll try. *Try* being the key work here.
She doesn't have a super feminine head (definitely a stock horse) with a short neck that looks over-muscled at the bottom. Very nice, refined throat latch. Her shoulder angle looks pretty good, slightly straight, and she has a nice, deep chest. She probably moves on the forehand just because of the difference in muscling from her front to back. I like her front legs, they're very straight, but she's a little tied in below the knee.
He back is a little long and looks a tad roached, though not terribly so. Her topline is probably going to take a while to develop just because of the length of her back. Her back legs aren't bad, very slightly sickle hocked. Her pasterns are nice, short and angled correctly and she has fabulous, big feet, though she looks like she stands on her toes.
I see absolutely nothing glaringly wrong with this horse and she's definitely cute and will look even better with muscle tone and weight.
She has a pleasing enough head and pretty colouring. She will definitely look much better, with some weight and conditioning.
She is long and has a roached back. She might be slightly cow-hocked. Her shoulder is a bit straight and I'd maybe like to see a little more neck on her, but it's not horrible. She is very tucked-up. I'd bet she carries frame, so you'd absolutely need to test her, if you ever decided to breed. However, at the moment, I wouldn't consider her near breeding quality.