sb is of a solid character: 某人很有个性。

too...to do/to be：太...以致于不。

be mixed up in: 及物短语从句，卷入..., 与...有牵连。

seem (to be) of a solid character: 似乎很有个性。

something that sordid：something so sordid. 那么卑鄙的事情

Sophie Neveu seemed of far too solid a character to be mixed up in something that sordid.

索菲耐芙似乎具有很强的个性，不会与那种卑鄙的事情有牵连。