What are your cousins like? literally, "how are your cousins."
"Quienes son tus primos" translates to "Who are your cousins" in English.
"De donde son tus primos" means "Where are your cousins from?" in English.
Como son tus padres
What are your cousins' names?
how are the girls -- How are they (all boys or a mixture of girls and boys)?
Tus primos (masculine or different genders) or tus primas (feminine).
Tus ojos brillan como el sol. "You eyes shine like the sun." Or "Tus ojos son como la luz del sol."
Tus ojos y cara son hermosas.
Tus ojos son tan bellos como el sol.
"Como estan tus padres" means "how are your parents" in English.
Translation: How are your classes? Possible reply: Mis clases estan muy bien = My classes are very good.
Como eres bonita? = How are you pretty? Que bonita eres! = How pretty you are!