You have a lot of things stacked against you with this little girl. The first is she’s a solid appy. Which means, even for breeding, she’s not ideal since she’s half QH and may not throw color. Appaloosas aren’t as “in” as they once were (there used to be two ApHC show associations in my state and now you’re hard-pressed to find any ApHC shows at all). If she were an AQHA she’d be worth more. If she were a solid APHA she’d be worth more. But as an ApHC, sad as it is to say, she’s just not going to have as much appeal to those who want a registered filly. Then add that she’s a solid ApHC and that decreases her value even more.
Honestly, she might as well be a grade horse. She’ll get used as a grade horse. Her bloodlines are fine, but they aren’t anything that sought after. She’s got cow horse on the AQHA bottom side and some notable ApHC names farther back on the top (Dreamfinder, Prince Plaudit), but she’s not a typical modern bred horse with specialized bloodlines for a particular event.
To get her sold, I would have her doing everything she can possibly do safely without risking her physical health and growth. Make sure she leads, ties, loads, bathes, clips, stands for farrier and vet. Do a lot of in-hand work with her. Expose her to anything and everything to get her 100% bombproof on the ground. Start lunging her for short periods on good footing to get her used to that. Keep her well-fed, well-groomed, and looking her absolute best.
I don’t know what you have her priced at, but for an unbroke, small, solid ApHC 2 year old filly, don’t expect to get much.
She’s cute as a button, by the way. I have an ApHC that I bought as a scrawny yearling (looked like a weanling). I gelded him, registered him, and fed him. He’s now 16 hands and build like a brick house. He’s out of an ApHC stallion and AQHA mare too, but he lucked out and got some color.
Good luck to you!