First off, welcome! Secondly, those scores are not bad--actually they're quite good. (If you include the confidence interval/standard error of measurement, they are not significantly different from GT range.) Whether they turn out to be representative of your daughter or not, they still represent a very small chunk of the population. Onto the meat: the KBIT is a screening instrument--all right as far as it goes, but not to be compared to a true comprehensive cognitive assessment, such as the WISC or SB, or even the KABC, DAS, or WJ. I've used it for gifted screening in the past, but that was more a function of the trade-offs involved in testing many, many children in a short period of time. Many psychologists prefer it for young children, because it is short, and they choose to reduce factors of fatigue, at the expense of detail. I wouldn't call it unreliable per se, I just wouldn't ask it to do more than that for which it was designed.
Another significant consideration is age. Early childhood scores are notoriously unstable, partly due to the vagaries of maintaining optimal test behavior in a small child, and partly due to the wide normal variation in developmental curves. In another two or three years, you'll probably be able to obtain a more accurate picture of her cognition.
If scores are important to your family, then, by all means get a WISC-V or SBV done, knowing that they will be subject to the same early childhood score instability, but more wide-ranging in cognitive domains. However, once you've done one, you will close the door on retesting with the same instrument for another two years, as that is the minimum interval for valid retesting.
At this point, I would be less concerned with exact scores, and pay closer attention to qualitative concerns. An IQ of 130 and an IQ of 140 are not that different at age 6, in terms of feeling that kindergarten is not academically challenging or engaging. How she responds to that frustration can be affected as much by her temperament and (especially) her classroom environment as by her LOG.
