Are these sentences fully natural?

She kept vacillating between hope and despair.

She kept wavering between hope and despair.




Choose the Right Synonym for vacillate

hesitate , waver , vacillate , falter mean to show irresolution or uncertainty.

hesitate implies a pause before deciding or acting or choosing. hesitated before answering the question

waver implies hesitation after seeming to decide and so connotes weakness or a retreat. wavered in his support of the rebels

vacillate implies prolonged hesitation from inability to reach a firm decision. vacillated until events were out of control

falter implies a wavering or stumbling and often connotes nervousness, lack of courage, or outright fear. never once faltered during her testimony

Refer to Merriam Webster Dctionary.