UMG: How to Scale single child of vertical box?

Hello,
how can I scale a single child of a vertical box without the other children scaling as well?

Like in this Screenshot: https://assets.vg247.com/current//2016/11/ff15-screen2.jpg

I tried wrapping the child element in a size box but when I scale a single element of the vertical box it will automatically scale the other elements aswell.