She won't. She's almost as corrupt as her father. Don't forget, it's her husband Jared Kushner who accepted a 2 billion dollar investment from MBS.
Also, if she testifies truthfully, she'll be admitting to her own crimes, and to other things that will cost her real money. For example, one of the things she's going to testify about in this trial is how her father gave her several properties, but the properties were appraised using Donald's ridiculous appraisal logic, so that she would pay less in taxes. If she is honest, the IRS will be after her immediately.
By the way, there's a chance that she could have gotten out of this without testifying in open court, but her lawyers amateurishly missed doing anything by the deadline. And if you remember, Trump wanted a jury trial for this case, but his lawyer forgot to ask for one, so they got a bench trial, instead.
This kind of shit would be absolutely hilarious if there wasn't some chance that he'd become President again. This guy thinks he surrounds himself with "the best people", but all he can find are people who make elementary mistakes.
And the US President's biggest influence on the country is through his appointees. He actually has a few decent lawyers working for him now, but when the chips are down, he relies on these types of people, probably because they kissed his ass more, or swore allegiance to him or something.