I would not have bought that filly with the intentions of barrel racing. Barrel racing is very hard on the joints and legs, and it's better to start with a sound and correct horse.
However, I'd be interested to see what the INSIDE of her pasterns look like. Her bones might be correct on the inside, or they may be crooked as well.
I'm going through a similar issue with my 7-yr-old right now, who I"m training for barrels. I've had him just over a year, and a couple months ago he developed a very slight limp at the trot. He is put together pretty nicely, besides being a little bit pigeon-toed (but not bad). Took him in for a lameness eval and I find out he has crooked pastern joints on the inside on the X-ray ...... outside confo looks just fine.
So we're experimenting with wedge shoes and pads right now, and so far he's holding up.
If I had known he had this problem when I bought him, I would not have bought him (because I want to barrel race). But it's only emerged now, so I'm going to see if he can stay sound for barrel racing. If not, I will find him a new home with a career that's less stressful on the joints. Time will tell.
Anyway, you certainly can try with this filly, but be prepared to spend a lot of $$$$$ on vet lameness visits and farrier work. Is it worth the $$$? Maybe. If it's not, and if you don't have the $$$, I would find a different prospect that is structurally sound.
∞•*˚ Βгįťţαňγ ˚*•∞
It is not enough to know how to ride; one must know how to fall.