Plausibility check, Dowager Empress as modernizer?

[raharris1973]

In OTL, the Dowager Empress Cixi had effective political control over China from 1861 to 1908. In summary, history has not judged her favorably, although some have defended her against some of the accusations of her many detractors.

She had longevity and political skill going for her.

What is the plausibility of her having an influence that would have historians regarding her as more of a Catherine the Great or an Elizabeth? Or, her being a patron of Chinese self-strengthening as successful as that of the Japanese Genro in the Meiji era?

Was such a positive impact possible, or was her being reactionary and a spoiler of others' reform efforts the only thing that allowed her to be so politically successful and unassailable?