What does this expert from Shakespeare’s Twelfth Night imply about Olivia?

VALENITNE: So please my lord, I might not be admitted, but from her handmaiden donreturn this answer. The element itself, till seven years’ heat, shall not behold her face at ample view, but like a cloistress she will veiled walk, and water once a day her chamber round with eye offending brine: all this to season a brothers dead love, which she would keep fresh and lasting in her sad remembrance.