The real question here is whether the client list qualifies as a "trade secret" so as to get protection under the Uniform Trade Secrets Act. Client lists typically do qualify, but the determining factor is whether the company has taken reasonable steps to keep the information confidential.
The list itself, the actual list, may be company property. The former employee compiled this list as part of her job, and at least partially while on the clock, which indicates that it was part of her job to do so. Because of that, there is an argument that the company owns this list and by taking it with her, the salesperson is stealing company property.
That said, the former employee did compile some of this in her free time, and it may not have been an explicit part of her job. The former employer may not even know it exists. Furthermore, the information may be readily available, which would indicate it is not a trade secret.
The botXXXXX XXXXXne is that the list may or may not be protected, depending on how easily obtainable the information is and how well the company protected it. There is no definitive answer here, but you indicate that she could re-create the list from public data... in which case it is most likely NOT protected by the UTSA, and she would be free to use it to compete with her former employer.
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