OLIVIA Blame not this haste of mine. If you mean well, Now go with me and with this holy man Into the chantry by: there, before him, And underneath that consecrated roof, Plight me the full assurance of your faith; (4.3.1)
As readers we tend to focus on all the ways Viola's behavior challenges notions of gender and what it means to act "like a woman." When Olivia steps into the traditionally male role and proposes marriage to Sebastian, we're reminded of just how bold Olivia is. We might think Olivia is weak at the play's outset (when we learn that she's in seclusion over her brother's death), but by the time Olivia sets out to seduce "Cesario," we understand that Olivia is just as untraditional as Viola. Both women break out of traditional gender roles assigned to Elizabethan women (quiet, submissive, "pure," wearing a dress, etc.).