Some wood just doesn't want to be straightened.
It is possible to just leave twist and tiller it to still draw back in a straight line.
It requires enough width to adjust the string line as the tiller ing progresses and a fair bit of luck/patience/skill but sometimes it's just easier to let the wood bend in the direction it wants and to build the bow around that.
The character in the end result will also be well worth the effort if you succeed. I don't guarantee it will impress the girls tho'
Del