Shortly after President Bush announced that he would activate reserve military forces, Air Force reservist Jane Probst called her parents. Not to say goodbye or to allay their fears about a daughter facing active duty, but to ask a favor: Could one of you baby-sit?

Probst, like thousands of other reservists and military personnel, is scrambling to put her affairs in order in anticipation of that 24-hour notice to ship out. For families with young children, particularly those in which the mother is the reservist being activated, a major concern is who will take care of the children.

For the most part, child-care arrangements are left to the individual.

The military, which has limited day care at some bases, warns its reservists when they join to have a plan in place in case of a national mobilization. But the reserves have not been pressed into service for 20 years, and for many reservists today, finding alternative care for their children is proving difficult.

"It's not like 20 or 30 years ago where you have extended family right next door. It's just not that easy," said Monica F. Kalish, a nurse and former military officer who may be activated through the Army Reserve and would have to find care for her 8-year-old daughter.

Under ordinary circumstances, child care is a complex and sometimes difficult issue for two-income households in the Washington area.

But for military families, especially those in which both parents are on duty, round-the-clock child care often must be arranged for several weeks or months.

"They should have been planning for this from the moment they said, 'Yes, I'll be a reservist,' " said Lt. Cmdr. Michael Smith, a spokesman for the Defense Department and a member of the reserves.

Probst, 30, was asked by her unit if she would be willing to volunteer for a one- to six-month assignment in an unspecified location.

Probst volunteered for duty but was not selected by her crew leaders.

If Probst, who is trained to evacuate the sick and wounded, is ordered overseas, her husband, Fred, said he would be able to help with the children. But as a firefighter with the Montgomery County Fire and Rescue Service, Fred Probst's work schedule entails days where he works 24 hours straight.

The only solution, he said, was to ask his wife's mother if she would leave her home in New York to come to Howard County to assist with the children, ages 3 and 4.

"We want to keep their lives as normal as possible," said Fred Probst, 33.

Several mothers with children in the Lisbon preschool the Probsts' 3-year-old son attends have also offered to help the family with child care.

"It's so heartwarming," said Jane Probst. "People really understand what's going on."

Kenneth McDowell's wife, a nurse at the Bethesda Naval Hospital, left for the Middle East aboard the USNS Comfort hospital ship, leaving behind a 1-year-old daughter, Caitlin. McDowell, a banker who works and commutes long hours, said he is lucky that his daughter's part-time babysitter is able to keep her practically full time.

"My daughter is spending 10 to 11 hours a day at the sitter's. It is a stressful situation for me," he said, noting that the first sentence that Caitlin ever put together several days ago was, "Mama, bye-bye."

Julie M. Cockrill, 40, an operating nurse at Prince George's Hospital Center, said she feels lucky that her daughter is 19 and is headed back to college.

"My daughter is more independent," said Cockrill, a member of the 97th Command Army Reserve unit at Fort Meade. "If {she} were young, I'd be worried. {She} would need me more."

For other parents, particularly single women with young children and no other family in the area, finding long-term child care is harder.

Although military installations will not provide child care, officials give reservists a list of facilities in the area and in extreme cases will place the children of personnel with no alternatives in foster care, said Chief Warrant Officer Patricia A.G. Putman, family assistance officer of the Maryland National Guard.

Kalish, a nurse with Kaiser Permanente, said she left the military in 1985 after 14 years and went on inactive status because she did not want to choose between her 8-year-old daughter and the service. Kalish said she has received a letter from the Army, raising fears that she will be activated.

Kalish said she is not sure what she will do if she is ordered to report to a military hospital outside of the Washington region. She said her parents are elderly and her former husband also is in the military and could be in the Middle East already.

"My mother is 75 years old. It's not her responsibility to raise my child," Kalish said. "That's a big imposition, physically, financially and everything else. Some people don't mind giving their children over to other people to raise, but I chose voluntarily to get out. I would not mind filling in positions in local military hospitals in this area, but I'm not very willing to go anywhere else."

Staff writer Valerie Chow Bush contributed to this report.