Is it this is she or this is her?

It can be “this is she” or “this is her” depending on the context. In formal contexts—such as answering the phone at work—use a nominative case pronoun for a predicate nominative after “is.”

  • Caller: “Hi, I’m returning a call from Dr. Jones.”
  • Sarah: “This is she.”

In everyday situations, though, “this is her” is perfectly fine (“My grandmother sent me this photograph, and this is her next to the tree”).

The QuillBot paraphrasing tool is an excellent resource when you’re exploring formal and informal ways to use pronouns.