"Her tastes were very classic," another customer, who was inside the Bonpoint shop on Brighton Way at the same time, tells PEOPLE. "Very practical."
Among the purchases: sweaters in caramel and grey for a 10-year-old girl and a jacket and slacks outfit for a very young boy.
Other selections were a bit more "fanciful," the source says, including "a princess dress for a girl [of] about 8 or so."
Holmes also picked out a short gold dress and ruby red shoes, described as "very red carpet," as well as some beach-ready shoulder-strapped sundresses.
Like husband Tom Cruise, Holmes is spotted regularly at the upscale shop, which scents and color-codes its packages: pink for girls, khaki for boys. Other celebrity clients of the brand include Brad Pitt and Angelina Jolie, Julia Roberts, Salma Hayek and Jessica Alba.