[REUPLOAD] I figured I'd make this post eventually. I won’t repeat myself again afterwards, this is what makes most sense to me. I believe Edward Midford is likely anywhere from 18-19 years old. After breaking it down with the information provided in the manga regarding Weston College, we can estimate he is 18-19 years old.
— At Weston, it is stated that you start enrollment at 13. Also, 13-18, because Yana took inspiration from Eton, however Weston has SIX years, not five… This makes it impossible for sixth years to END at 18. However it also would not make sense to change it to 12-18 years, precisely because she took inspiration from Eton (year 9-13). It is also important to remember that Black Butler isn’t always historically accurate, we have seen this time and time again with certain aspects of the story. Regardless, Edward is 18 at a minimum. However, the age breakdown would end up like this:
First years start at 13, and end the year at 14.
Second years start at 14, and end the year at 15.
Third years start at 15, and end the year at 16.
Fourth years start the year at 16, and end the year at 17.
Fifth years start the year at 17, and end the year at 18.
Sixth years start the year at 18, and graduate at 19.
— The only exception to this rule was Ciel. He enrolled mid year and is still 13, and would technically have not enrolled until the next school year. But it is not impossible for him due to Sebastian being able to pull strings. He becomes a housemaster in short time after all, it’s not unrealistic to believe he gets Ciel enrolled early. He is an outlier, not the expectation.
— To reference, in CURRENT canon, Edward and his peers are 6th years and the current prefects.
This means their ages can range from 18-19 depending on when their birthday falls during the school year.
Likewise, since the previous prefects have since "graduated" (expelled, but would've graduated), they are now in that next age range of 19-20 again, depending on when their birthday falls.
Also to NOTE: the wikipedia for one of the prefects (redmond), has him listed as 18-19! (he WAS a sixth year, and no longer is, so it aligns with when he was.) This also lines up with Edward and his peers being the same age group when they’re sixth years too. This is consistent and lines up with the breakdown I have provided.
reference: https://kuroshitsuji.wiki.gg/wiki/Edgar_Redmond
— Regarding how this relates to his sister and his cousin:
Lizzie is stated to be a year or so older than Ciel.
Ciel turns 14 in the current canon soon, So Lizzie is actually probably nearing her 15th birthday.
Edward is older than her roughly by 4-5 years, and older than Ciel by roughly 5. :)
