Big Sister, Little Sister

Even thought they fight, Eva and Emily love each other immensely.  So much so that they want to do whatever the other does, and vice-versa. This primarily is about Emily wanting to do/not do what Eva does/doesn't do, but Eva is guilty of it also. If Eva wants to quit ballet, so does Emily. If Emily is taking gymnastics, Eva wants to do it, too.  How can I get them to do the things they truly enjoy because they enjoy it and not because the other one is doing it?  How can I get them to do things independent of the other? Or, is this normal for same-sex siblings 2 years apart?

I think Emily is really good at ballet; she definitely improved the most over the last year, but Eva was only going to take ballet next year to get the pewter goblet (they get it after 3 years and every year after of ballet). I took care of that by getting them the goblet as their recital gift.  Now Eva knows she doesn't want to do ballet, which is fine because she is better at other things, but because Eva isn't taking ballet, Emily says she doesn't want to either.  I think, though, that Emily has admitted that she does want to do ballet next year, but I'm not 100%. 

Emily chose gymnastics as her summer activity, which is great.  It's really good for her, it's something different with different kids, and she loves it.  While waiting during her class, Eva says she wants to do gymnastics.  And I know she really doesn't because I asked her before.

Eva picked horseback riding camp for the summer.  Emily didn't want to do it, and I'm glad. Eva's best friend is taking it with her, and Emily would have been left out. Plus, I think they need to do things on their own sometimes. 

In mid-July Emily will start a swim school to learn all 4 strokes before joining the swim team in September.  Eva will join the swim team in August (she knows all 4 strokes already).  This is a year-long activity, swimming twice a week.  They will also both take piano next year. This will be Eva's 4th year and Emily's first.  Plus, this will be their first year at a new school.  Should I let them do another event separate from each other or are these two activities enough?  Eva is looking like she will want to take horse riding lessons (plus, there is a new place that opened on our street - 4 houses down) and Emily will want to do either ballet or gymnastics.

What to do. What to do.