Darkening Dyed Hair?

I messed up! How can I darken this to a more black cherry/burgundy? We dyed it less than 24 hrs ago and my natural hair color is dark brown. Only thing I know of for sure my sister-in-law used was Ion sensitive scalp lvl 30 developer and she hasn't told me the brand, color or type(perm, semi, demi) used and I hate it, makes me feel like a back alley strawberry shortcake. My brothers hair, which is the same dark brown, turned out a beautiful dark burgundy. We used the same stuff from the same bowl and I'm at a loss as to why did this compared to his.