Frankie's an ectomancer. Not only can Frankie see and communicate with ghosts, she can also take them into herself for a time if she needs to borrow their skills, knowledge, etc. She can also control ectoplasm.
She can perform a type of necromancy in that she can use ectoplasm to create a covering over the animal's (she can but she won't do people) bones in order to make a 'skin'. Here's an example via Harry Dresden and Sue.