If you really want a jumper you should look for another horse. There is no guarantee this horse will ever have a decent enough conformation to make any sort of sport horse. Being 1 and a half you'll have to wait 3-4 more years before she can even start jumping. That's a LONG time. You might want to look at slightly older horses if you really want to jump.
There are plenty
of great rescue horses out there, that with work can become great jumpers. Check your local shelters - you're probably safer there as you'll have as accurate information as they can possibly give.