Original sentence in the novel is:
何かしらの手は打ってくるだろう
A post in this site shows that it is a particle used more by females, while tangorin also shows it to be used as the meaning of "head", aside of the usage as a particle to mean "I wonder".
I think I'm supposed to treat it as a particle, but then there is the の particle that just confuses me. Can someone please explain the usage of かしら with の in this context?