MICHELLE GRACE, president of the senior class at Germantown High School, has one more chance to show her leadership ability to the students who elected her to represent them.

It'll be painful, but I hope she seizes the moment. If anyone can muster the character to pull off disappointment with aplomb, this lovely 18-year-old can.

In addition to being president, Michelle has also been editor of the school paper, captain of the softball team, starting center of the basketball team and - I love this - the only female on her school's football team.

She's also juggled the demands of her advanced-placement classes with her duties as an office aide for everyone from her deans and coaches to teachers and athletic directors.

That she manages to do this with a ready smile is icing on the cake that is Michelle, affectionately known as "Mickey" to her 1,145 Facebook friends.

But Michelle isn't perfect. A chronic over-sleeper, she admits she's been tardy to school about 40 times this year.

Last week, it caught up with her in a heartbreaking way.

Because she was late to her graduation practices - six sessions that started promptly at 8 a.m. - she was forbidden to participate in today's commencement ceremony (a possible tardiness consequence that she admits was made clear to all students).

So she won't march into the auditorium with 250 classmates, assemble with them in the first rows, hear her name announced or bound across the stage to receive her diploma while her family and friends cheer.

Instead, she'll sit with her parents in the audience and receive her diploma after the pomp and circumstance has subsided.

To me, when she was handed her punishment, the best thing Michelle could've done would have been to quietly accept it (the way that two of her classmates - also tardy and forbidden to participate - have already done) as an unforgettable wakeup call.

Instead, she wrote an impassioned letter - which she sent to community and elected leaders and to the Daily News - asking our help in convincing school administrators to reconsider.

"Despite my lateness throughout this year, I feel as though I have earned this right, through my dedication of service and through the many sacrifices I have made . . . over the years for this school," she said in her well-written plea for advocacy.

She went on to say that, while she accepted responsibility for her actions, for Germantown High to ban her participation would further punish those she admits she has sorely disappointed - "my parents, my church, my teachers and all of the people who have supported in my educational high school journey."

Let's just say that Michelle's letter did not sway Germantown High School's no-nonsense principal, Margaret Mullen, who stood by her decision yesterday.

"Michelle is a good girl, but she was late to all but one practice" - - "and she showed up with attitude," says Mullen.

If they let Michelle slide, "What message would we be giving the 250 kids who showed up? What would we be teaching our younger students about consequences of decisions - the good ones and the bad ones?"

Mullen says that some students were upset to learn that Michelle had lobbied outsiders to change the school's decision.

They expected better of her.

"We're trying to teach the children to be good role models to each other," Mullen said.

To be fair to Michelle, I don't think she's necessarily trying to skirt the consequences of her actions. I think, maybe, she's just shocked to learn there are consequences.

As she tells it, she was allowed to "get away with things"- mostly tardiness - during her time at Germantown High.

"When you're a good student, and you don't get in trouble, I think they let you slide more," says Michelle.

She says that she never once got a detention or suspension for lateness. Mullen counters that Michelle was given detentions; whether she showed for them is another story. As for suspensions, Mullen said that she didn't have Michelle's records handy to comment either way.

"Why come down on her now, with graduation?" wonders Michelle's mother, Dana. "It just seems harsh. If she'd been suspended for lateness over the past year, it would have been an appropriate punishment. She might have learned from it. But no one made a big deal about it. It seems like payback, now."

Me, I think it's a long-overdue lesson that Michelle - sweetheart though she may be - dearly needs to learn.

Especially if she hopes to succeed at West Chester University in the fall, where her professors, I daresay, won't cut her the slack she says that she was given at Germantown High.

"I'm bummed, but I'm getting over it," Michelle told me yesterday, her optimism returning.

"Unlike a lot of my classmates, I know I'll be attending another graduation in four years. I'm just disappointed to be letting people down. Including myself."

Finally, words worthy of a young woman whose last name is Grace.

E-mail polaner@phillynews.com or call 215-854-2217. For recent columns:

http://go.philly.com/polaneczky. Read Ronnie's blog at http://go.philly.