Power and control is represented by Juliet’s father forcing her to marry.
Juliet’s father is unhappy with his daughter’s desire to make her own choices. Juliet has already married (and spent the night with) Romeo, and she does not want to marry Paris. Her father has chosen Paris, and he will not take no for an answer.
Hang thee, young baggage! disobedient wretch!
I tell thee what—get thee to church a Thursday(165)
Or never after look me in the face.
Speak not, reply not, do not answer me! (Act 3, Scene 5)
It never occurs to Capulet that his daughter should decide her own destiny. In their society, he has the power to choose her future. She is his daughter, and his property. He can use her to further his goals or increase his standing in society. Her wishes mean nothing to him.
The fact that Capulet used his power over Juliet to control her is one of the main causes of the tragedy. The direct result is her death and Romeo’s, resulting from her ill-advised scheme to fake her own death.
Power and control are most certainly seen here in the characters of Lord and Lady Capulet. (It is important to note, however, that the early part of this scene involves Juliet and Romeo ending their wedding night together and wishing/convincing each other the nightingale over the lark.) It is when Romeo leaves and Juliet's parents enter the room that the power struggle truly begins.
Lady Capulet first tells Juliet that Lord Capulet has ordered her to marry Paris on Thursday. Juliet is distraught. She assures her mother that, "He shall not make me there a joyful bride!" Lady Capulet (as well as Juliet) are forced by society under the power of the father. It is at this point that Lord Capulet enters and is disgusted by Juliet acting this way about his order. I'm afraid it gets worse even than the quotation above!
Thursday is near; lay hand on heart, advise:
An you be mine, I'll give you to my friend;
An you be not, hang, beg, starve, die in the streets,
For, by my soul, I'll ne'er acknowledge thee,
Nor what is mine shall never do thee good.
Trust to't. Bethink you. I'll not be forsworn.
In other words, Lord Capulet is exerting his paternal control by demanding that Juliet marry Paris. And worse, he is threatening to disown his only daughter if she does not! He says that she can simply "hang, beg, starve, die in the streets" because he will never "acknowledge" her again.
In conclusion, it is interesting to note that it is because of the fetters of society that Romeo and Juliet have had any problem at all! It is all about who is given the power and control. Because the two lovers have neither power and control over their love nor the power and control over others to convince them of their love, the two TAKE control by taking their own lives: the only item they have control over.