By Doris Rochlin

Doubleday. 258 pp. $19.95

As Doris Rochlin's second novel opens, Linda Jo Burke Merceau, 25, is doing her best to care for her 6-year-old son, Paulie. After seven years of marriage, her wealthy and overindulged husband, Buddy, recently left to "find out who he was." Struggling to improve her life, Linda Jo wrestles with the responsibility of taking care of herself and her son, "a sickly, timid kid, not the feisty sort who'll make it in this world." Although frequently impatient or exasperated, Linda Jo is also perceptive and determined.

Linda Jo and Paulie have recently moved back home to suburban Washington with Linda Jo's mother. Her mother, Juanita, and her older brother, Franklin, have lived alone in the house near Friendship Heights since Pop was killed a year ago when he was hit by a bus. Both Linda Jo and Paulie are having some difficulties adjusting to Linda Jo's, well, crazy family. Juanita, a retired electrolysist, is a maniacal worrier. Obsessed with even the smallest possibility of illness or accident, she turns the most harmless activities into life-threatening perils.

" 'Smile for your grandma, Paulie,' my mother commands. 'You have a nice swim lesson. But tell Monte no high dive.'

" 'If Monte thinks he's ready . . .'

" 'You ever hear of broken necks? Snapped spines?'

" 'No matter. He'll pass out from indigestion.'

" 'Why do you say that?'

" 'The stuff you let him eat. A hot dog,' Juanita sniffs. 'You ever read "The Jungle"?' "

Juanita's world is absurd, often humorous, though it can also be unsettling and frightening.

Raised on such grim stories, Franklin not surprisingly is agoraphobic. He has not left the house in four years and devises little activities to keep himself occupied. He perfects magic tricks, invents recipes and sketches birds. His latest project is reading the 1968 Encyclopedia Britannica. Venturing out of his room only when he is certain there are no strangers in the house, Franklin readily admits that his life is a mess, but asserts that his judgments are sound.

Portrayed with warmth and humor, these are endearing and funny characters. Rochlin keeps the narrative moving with passages such as Franklin's recounting the time he and Pop went camping in a leaky tent during a rainstorm so that Franklin could learn self-reliance. Just as delightful is Linda Jo's recollection of the afternoon when Pop taught her and Franklin to dance in the deserted old Spanish Ballroom of Glen Echo Park:

"Pop moved like someone balanced on a drift of air and breathlessly I followed, astonished at the grace with which we moved. Whirling through the gloom of shadows into sunny light and back into a velvet dusk and into light again, we circled the big room. . . . Franklin and I stood face-to-face, gazing over one and another's shoulders, the gaucho and the senorita, frozen in the posture of the dance, till we exploded into giggles." Pop's goofiness is the answer to Ma's gloom, and laughter the ingredient that checks all pessimism.

Yet "In the Spanish Ballroom" is more than lighthearted entertainment; it is also a story of self-reliance, personal growth and courage. Things begin to change when Juanita suffers a heart attack.

With her mother's illness, Linda Jo finds she must now take care of her mother and Franklin as well as herself and Paulie. And as she assumes this responsibility, she becomes self-reliant, realizing she cannot hope or expect Juanita, Franklin or even Buddy, who now reappears, to resolve her problems or improve her life.

A successful combination of whimsy and wisdom, "In the Spanish Ballroom" is a sweet and perceptive novel that reminds us that a little bit of humor and courage can overcome just about everything. It is not overly dramatic or powerful. It does not sweep you away with its message. Instead, "In the Spanish Ballroom" subtly manages to be uplifting and hopeful without ever being maudlin.

The reviewer is a New York writer.