Generally speaking the smaller the magical species the smaller the home. Nobody likes cleaning anything more than they have to do regardless of what world they're on and whether they use magic to assist with housework or not.
The Palace is the largest private dwelling in the realm. The Chief Witch's magnificent (by her standards) home is not much smaller and it is believed the only reason she did not outdo her fairy rival was to avoid any magical confrontation the Witch herself hadn't forced on the Queen.
The Palace also has the biggest collection of fine furniture, portraits, jewellery, porcelain, gold and silver objects anywhere in the realm and would rival most places on Earth comfortably too. There is no way the Fairy Queen is opening her Palace to the general public on the grounds there is far too much of value to put at risk so "spotty herberts" can tour the place. Nor can the Queen be bothered to put in a safe place the more valuable items. Still she has put a curse on each of her most prized possessions. You steal from this woman at your own risk.