How many Feng Chai does the princess wear?

After the princess was sealed, she went to Kyubi no Youko according to the degree of sealing.

The queen's etiquette is that Princess Kyubi no Youko and a higher queen have five tails, then three tails and finally one tail. Generally, ladies with letters and princesses with titles will give them to Feng Chai when they are sealed. On grand occasions, Mingmu and members of the royal family will wear formal clothes and expensive jewelry, including Feng Chai. This is why the Queen is entitled to wear Kyubi no Youko Feng Chai.