The phrase "announcing that she will" is correct and usable in written English.
It can be used when someone is making a declaration about a future action or decision.
Example: "She is announcing that she will be stepping down from her position at the end of the month."
Alternatives: "declaring that she will" or "stating that she will".
SARAH PALIN, on announcing that she will not run for president.
Louise Arbour, its chief prosecutor, has dismayed many by announcing that she will be leaving her job in September, a year ahead of schedule, to become a judge on Canada's Supreme Court.
Mr. Schwarzenegger is expected to propose new measures this year, and now Michelle Obama has joined the movement, announcing that she will make fighting childhood obesity a special cause in the White House.
Why I have sympathy for the departing PCC chair Baroness Buscombe has fallen on her sword by announcing that she will not seek to extend her three-year stint as chair of the Press Complaints Commission.
Since the Muslim holy month of Ramadan began last week, the ambassador has made another widely reported gesture, announcing that she will fast like devout Muslims from sunup to sundown each day for 30 days.
"I still love the riding, that hasn't changed at all," she said at Chelmsford City on Thursday evening, a few minutes after a winner and three days after announcing that she will retire at the end of the Flat season.
In the space of less than a year, Hillary has gone from proudly calling Republicans her avowed enemies to announcing that she'll #actually be their savior.
Ms. Bhutto has announced that she will return on Oct. 18.
Dixon has announced that she will run next year.
She recently announced that she will name her son Benjamin, too.
HILLARY CLINTON has announced that she will not continue in her job for a second term.
