Tienen la misma edad, nacieron en el mismo año/ son del mismo año.

(Ellos/ellas) Son de la misma edad, nacieron casi al mismo tiempo.

Hi ! "They're the same age" = in spanish the translation is = " ellos/ ellas tienen la misma edad ". You can't use the verb "to be"/ "ser", the correct form is using the verb "to have" / "tener". "They were born around the same time " = "Ellos/ ellas nacieron alrededor de la misma fecha ". In this sentence the word "time" cannot be translated as "tiempo", because it wouldn't be an appropriate expression if you're talking about the date of birth. You can also translate: " ellos/ellas nacieron casi al mismo tiempo " ( they were born almost at the same time ) I hope that my explanation has been useful. Bye Sofía.

"Ellos/as tienen la misma edad, nacieron aproximadamente al mismo tiempo"

"Ellos/ Ellas son de la misma edad, nacieron al rededor del mismo tiempo." Hope I helped you, have a nice day! :)