Hi All, Hoping someone can help me

I'm making a cake for a family friend this weekend, the Daughter is graduating High School and I have already made a sugarpaste figure of her for her cake, but I was just thrown a curve ball when they added their nephew (who loves with them) to the celebration as he just had 8th grade promotion.

I've changed my original design to now make a 1/4 sheet cake and diagonally divide it with one side Congratulating the High School Graduate with her figure but I'm stumped on what to put on the other side, luckily he is attending the same high school so I have put the school logo in the middle but I just can't think of what to write

I'm not from the US originally so the whole promotion graduation thing is foreign to me.

So far I came up with welcome to High school but that sounds kinda urgh to me, was wondering if I just put Congrats "name" class of 2015 on that side

Please anyone if you have any ideas post them here, the cake is due on Sunday

Thanks in advance

I was going to suggest exactly how you describe the design I did that once.
As for what to write: I suggest what you said: Congrats "boy's name" *&* welcome to high school's name (example: Elwood High School)
If you have room and want to maybe pipe/add small things that are of interest to him: baseball &/or bat, science flacks; math problems; something along that line.

thanks kakeladi just spoke to mum/aunt and she suggested the same thing lol

ok now onto baking lol

thanks again