Passing stool after almost every feed is common at one month old, especially in formula-fed babies, and on its own does not mean she is absorbing feeds poorly or that her weight gain will be slow. This is a normal reflex where feeding triggers the gut to empty, and many babies this age do it several times a day without any problem.
Next Steps
What matters more than how often she passes stool is whether she is feeding well, wetting 6 or more diapers a day, and gaining weight steadily week on week. Keep a simple weekly weight check going for reassurance.
Health Tips
See your pediatrician soon if the stool becomes watery, has blood or mucus, smells unusually foul, or if her weight gain slows down over a week or two.