That depends. What do you mean by “hearing”? Is it a motions hearing, a status hearing, or (most likely) a preliminary hearing? Is it adult court or juvenile court?
Assuming it’s a preliminary hearing in adult court, it is unlikely that they will be able to use your daughter’s police statement at all. I don’t know Indiana’s evidence rules, but in every jurisdiction I know, it’s inadmissible hearsay. In all likelihood, if your daughter doesn’t show up, one of two things will happen: either the case will be continued to another day, when your daughter will be asked to show up again, or the case will be dismissed outright.
If your jurisdiction is like my jurisdiction, here’s what will happen. A few minutes before the hearing, a prosecutor will pull your daughter out into the hallway and discuss her testimony with her, making sure it is consistent with the police statement. Then, when the hearing begins, the prosecutor will call up your daughter. Someone will swear her in. The prosecutor will say something like, “Hello Purpledaughter. Can you tell us where you were at 5:30pm on Tuesday September 25th?” She’ll answer, then the prosecutor will say, “And do you see anyone in the courtroom today who was there at that time?” And she’ll point at ex-boyfriend. Then the prosecutor will say “And what happened?” And she’ll tell her story. If she leaves out anything important, the prosecutor will ask her about it.
Then the defense attorney will start asking questions. For a preliminary hearing, he’s not (usually) trying to play any games, or poke holes in the victim’s story. He knows that he’s not going to “win” in this hearing, so he just wants to bring out any facts that will help him at trial. He’ll ask if she’d been drinking. He’ll try to pin her down on the exact words that were used during the incident, so that if it changes later, he can point back to her earlier testimony. Likewise with the exact order of the events. If the event is clear in your daughter’s mind, and she’s clear on her direct testimony (when the prosecutor is asking the questions), then there is often very little cross-examination from the defense.
Then the judge will tell Purpledaughter to step down, and the prosecutor will call up the officer who showed up at the incident, who will testify in a fast bored monotone. Some prosecutors like to call the cop first, it’s up to the individual prosecutor.
These hearings (assuming, still, that it’s a preliminary hearing we’re talking about) are usually pretty quick. The burden of proof is very easy for the prosecution to meet, so neither side puts a lot of effort into them. Of course, if the complaining witness fails to show up, the burden of proof suddenly gets a lot harder to meet. It’s possible to get it with only the cop’s testimony, but it’s not easy.
For the witnesses, the worst part is waiting for three hours on an uncomfortable bench for your case to be called.
On a side note, you or your daughter need to tell the prosecutor that she’s been in touch with the defendant and defendant’s mother. The judge might order them to stop.