Let me know what diet she was on before day.. as carrots, beetroot puree might make the stool colour pink ..

Are the stools loose or very hard? At this age,give 2 solid meals a day including curd and Banana in the diet in addition to whatever you prepare at home. Give 4 milk feeds including one top formula feed using a spoon and katori and rest breastfeeds. Maintain strict hygiene in feeds. Get a routine stool test done,collect it either in any clean bottle or a plastic vial from a path lab. Let me know the results,till then follow above instructions.