Even if they are the same height, Eleanor is older than Elena. 
Both are dark skinned, red eyes and red hair. 
You can tell them apart easily by their pendants. Red is Eleanor while blue is Elena
They are usually emotionless but they love you with all their heart.
Both wear their hoodies from their world. 
Even if you couldn't give them the world they know that you love them just as they do. 
Even if they don't say much their actions are just enough.
Eleanor is 19 years and Elena is 17 years old