Legal Question in Landlord & Tenant Law in Massachusetts

If you are renting an apartment from someone, they do not have the right to charge you additional expense for having a visitor; even for three weeks. I sincerely doubt that a charge of $5 per day is reasonable for the cost of your friend taking a shower or 5 showers per day.

Without reading your lease, I am not sure you need her permission to have a guest for three weeks. However if you do need her permission to have a guest for more than two weeks, then I suppose you need her permission. She however has to be reasonable in granting such permission.

If the $105 is not a big deal for you, it is not worth arguing about; but if you have a weekend guest does she intend to charge you $10.00.

She is your landlord, not your warden nor is she a hotel manager. It is your call but to answer your question it is not the norm.