Welcome to PT, and I am sure you will love it here. Hmmm...a skinny mini, huh? I think if the vet checks her out, says she is fine, and is acting healthy, then wait and see. You could have her tested for hypothyroidism...which would speed up her metabolic rate, and could explain the skinniness. What about finding a food she adores? Has she been tested fo worms? Is she being spayed today? Let us know! And, again, welcome.