Head Boy - Head Girl?

"A Head Boy or Head Girl is a Seventh Year student who has authority over prefects and students at Hogwarts School of Witchcraft and Wizardry. They wear a badge.
"At the beginning of the school year the Headmaster appoints, new prefects as well as one Head Boy and one Head Girl from all of the seventh-year students. On the Hogwarts Express, the Head Boy or Head Girl of their house has to go through all the things that is needed to know to be a prefect. Most Head Boys and Head Girls were once prefects, although that is not a necessity; one example being James Potter, who was Head Boy despite not being a prefect.
"The trophy room contained a list of Head Boys (and presumably Head Girls). The Head Boy and Head Girl are in charge of the prefects and should be an example to the other students. Head Boys and Girls also had the special privilege of being able to use the Prefect's Bathroom.

"Known Head Boys and Girls
Albus Dumbledore (1898-99)
Tom Marvolo Riddle (1944-45)
James Potter (1977-78)
Lily Evans (1977-78)
Bill Weasley (1988-89)"

from: Harry Potter Wiki link

i believe they still have the same common room and dormitories as the rest of their houses. and yes, they can definitely take away points; not sure if they can award them.

hope this helps! n_n

they almost have the same power that teachers do but not all of them, they do give detention and stuff but i don't think they can take or give house points and yea i guess the do have their own bathroom but idk about their own common rooms.
glad i can help :D

"Head Boy/Head Girl
There is one Head Boy and one Head Girl each year at Hogwarts. These are students in their seventh year who are given some of the responsibility of maintaining order and administering discipline. They are also in charge of the Prefects. Percy Weasley was Head Boy in his seventh year. James and Lily were also Head Boy and Girl. Apparently, one does not have to be a Prefect every year to become Head Boy, since James was not a Prefect in his fifth year but was made Head Boy in his seventh."

from link

they do have their own bathroom and they can take\give points