I don't know that there is a place to "find" the answer, but I'm willing to throw out some general thoughts, for what that's worth.
1) Who is the fundraiser's contract with? (This assumes there's some kind of fundraising company involved here, and this isn't just being run by the school.) Is the contract with the school, and she is signing just as the school's representative? If so, it is the school's income. I don't understand why a checking account would be set up under anyone's tax id number other than the school's. The school will need to report that income on their tax return.
2) Why in the world would the teacher want to open the account under her name with her tax id number? If it's an interest bearing checking account, the bank will report that interest to the IRS, and when she doesn't report it on her tax return, then her tax id number will be flagged by the IRS. If it's not an interest bearing checking account, not as big an issue. Unless of course, she get's audited for other reasons--then she'll have to explain what all that income is and why she doesn't pay taxes on it.
3) So you have one teacher getting all the money and deciding how it is all spent? Depending on what the fundraiser is and how the money is being handled, sounds like you're opening yourselves up for embezzlement here. How do you know that you aren't raising $5,000 instead of $2,000? How do you know all the money will be spent on school related items? Someone needs to set up some basic controls and guidelines to protect the school.
4) As for reporting the income on a tax return--the money has to go on someone's tax return. If not the school's, who else's? Assuming the school is a 501(c)3 organization, the money has to be spent fulfilling its mission, so there's another reason for the school to take more control over this. (There was another post a few weeks ago where someone excerpted something off the IRS website that dealt with appropriate expenditures for a tax-exempt organization--might want to dig through a few old posts.)