The White House said yesterday that an NBC proposal to air a special featuring President Carter and perhaps his daughter, Amy, which would be directed to a national children's audience is "only one of a large number of ideas" it is considering at this time.

"The President only has limited time," an administration spokesman said, adding that "right now, Amy is very busy attending school."

The spokesman said the White House has had hundreds of requests for the President's time and that there are "no immediate plans" to act on NBC's proposal.

NBC first suggested such a program last November, when it asked the Carter transition team if the President-elect and daughter Amy could appear the afternoon before the Inaugural to brief youngsters on the upcoming event.

NBC subsequently suggested that perhaps President Carter and his daughter could appear in either a Saturday morning or early prime-time interview special during which they might answer questions that would interest children, on such subjects as Amy's homework habits, the family's TV-viewing rules and the like.

Last week in Miami, an NBC program executive told network affiliates that the idea for a "Jimmy and Amy" show hadn't been turned down by the White House and was still a possibility.

Odds and ends: Local ratings books for the month of January gave Channel 7s "7:30 Live" a new lease on, well, life. The ailing show increased its audience by 50 and 60 per cent last month, depending on which ratings service is cited, and station executives have decided to ride with it at least through the spring . . .

Susan Hampshire, who is stunning the public broadcasting crowd as Lady Glencora Palliser these days, will be on hand sometime during the week of March 13-20 to help Channel 26 with its spring fund drive . . . and American Vegetarians has announced it will file a complaint today with the Federal Communications Commission against NBC.

They will charge the network and its affiliates "have for several years denied public service time to American vegetarians and other non-profit vegetarian groups seeking to air spots which focus on meat as a cause of world hunger, disease and animal suffering."

As they are saying on Manhattan's Sixth Avenue this winter, ho hum. ABC won another NIELSEN RATINGS WEEK - its 17th out of 22 so far - taking 8 of the top 10 spots for Feb. 14-20.

But there were a few surprises. NBC's "Saturday Night's venture into Sunday prime time turned out to be a disaster, as the program finished 62 out of 69 ranked for the week.

It was up against "Secrets," ABC's tale of a nymphomaniac which finished sixth and CBS' "Delvecchio," which finished in the middle of the pack.

"The Spell," NBC's lead-in on Sunday's "Big Event," finished way up in 17th, which should indicate to the Saturday Night crew they're not at all ready for prime time.