Two months to go. Fifty-eight nailbiting, maybe-they've-forgotten-me days. On April 15, The Letters will arrive. About three seconds later, the high school seniors of the earth will know where they can - and probably where they will - go to college.

Meanwhile, these are the times that try seniors' souls. It's wait and wait and wait some more. 'Tis the season to be jumpy. But out on Bull Run Court in Vienna, Va., a senior who might be among those going off the deep end just sits, plays her flute and calmly turns the pages of the calendar.

She is Becky Cuthbertson, the pride of Marshall High School, and she is going for broke. She has applied, in alphabetical order, to Duke, Harvard, Princeton, Virginia, Virginia Tech, William & Mary and Yale.

No Hogwash State for this senior. She wants the best. So, like hundreds of other seniors, it is a question for her of where, not whether.

The fact that Becky Cuthbertson has the credentials to dream her bit-time dreams no longer matters very much. The grades have been in since last spring, the recommendations since last fall. She has writter her autobiography in 500 words or less so many times that she's quit counting.

Becky still worries about the B she got in freshman English - the only one she's ever seen - but that's water under the bridge. For now, she is concentrating on avoiding Senior Slump - and sending off great mindwaves of hope in the direction of seven particular admissions officers.

"I really don't have any real first choice," said Becky, a slim 17-year-old with fine-china features. "And I'm realistic. Princeton only accepts about 20 percent and the others are about the same. I'm not that smart. There are a lot of people as smart as I am."

If that were so, the rest of us would have outgrown the Sunday crossword long ago. Try these Cuthbertsonian numbers for size:

She scored 710 of a possible 800 on both Scholastic Aptitude Tests. That places her in the 99th percentile nationally. There is no 100th.

She is a member of the National Honor Society and is a National Merit semifinalist. Only a semifinalist? "Well, I don't find out about the finals for another couple of weeks." Oh.

She is second-chair flutist in the all-regional band. She is photo coordinator of the year-book. She did environmental research last summer in Southwest Virginia. And despite that icky old B, she ranks 16th in a class of 432.

But Becky claims that, until this year, she had no idea how she stacked up with "the competition" those other smarties who are just as determined to go First Class as she is. She says she was a little stunned to find out.

The setting was an annual reception thrown for all Washington-area applicants by one of "her" seven schools. "You wouldn't have believed it," she said. "You wouldn't have believed the brains there."

Cuthbertson says that much of the gray matter was attached to male bodies. But she stresses that she applied to seven coeducational colleges so she could never say to herself that she shirked a challenge.

"I was really kind of leery of going to an all-women's school," she said. "I'd just be hidden away from the competition for four years. I've been competing with guys all my life, and I'd be competing with them when I get out. So . . ." And she turns her palms out and up.

Word-of-mouth about the dating game was a factor, too. "The social life at women's colleges is really a bummer," she said.

Becky is tilting toward the Ivies - assuming they tilt toward her - because she feels an Ivy degree might help in her eventual career aim: to be an environmental scientist or an environmental lawyer.

"But I've been influenced by the attitude that you can get a good education anywhere," she said. "I don't know what to think."

That would come as something of a surprise to her family, for, according to her mother, Ida Cuthbertson, Becky was a definite, cerebral child - "always curious, always thinking, always asking questions. When she was very young, she cried a lot because she wanted to know what was going on."

Still, it is a long jump from there to Cambridge or Old Nassau, and Becky claims that the decision to try strictly was her own.

"My parents didn't pressure me at all," she said. "They both went to state schools. But after all my scores and grades were in, I thought: 'Why not go for the best?'"

But having fired her salvos into the mailbox last fall, she can only watch the family's mailbox this winter. "I would like to be able to relax," says Becky Cuthbertson, "but I can't." Not until the Ides of April.