What does the author most likely mean in line 18 when
he or she states that "love... paints a phoenix to her
eyes"? What is the figurative significance of this line?

The poem is Verses Written By A Young Lady on women born to be controlled

The notion of the phoenix probably means that love gives her hope for a change or better life. The phoenix symbolizes being recreated or reborn.

Explanation:

It is likely the author means that women often feel like love is their escape or that once they find a husband they can be reborn from having to succumb always to the wills of men in her life. A phoenix is a mythological bird that is reborn again after burning, emerging from the ashes as reborn. Love gives them hope for a time but then the "disturbed rest" and "painful signs" suggest that she suffers because of love as well. The entire poem laments the position of women at that time which was conceived as normally controlled by and subservient to men.

the use of “as” in the example to draw the resemblance. some more examples of common similes are given below. common examples of simile. our soldiers are as brave as lions. her cheeks are red like a rose. he is as funny as a monkey. the water well was as dry as a bone. he is as cunning as a fox. simile introduces vividness into what we say.