None of those foods sound particularly fibrous, which helps when it comes to bowel movements.
I usually go 2 - 3 times a day. Then again, I eat a fair bit and have around 50g of fibre a day.
I'd consider once every day to be a a minimum, once every couple days to be borderline healthy. Every 10-15 days? Something's messed up there. Make her a smoothie and slip some Metamucil in it. Do her a favour.