I can continue this sentence, though it's ambiguous who "she" refers to. Here are two possible continuations:

"The doctor phoned the nurse because she was late **for her shift and hadn't notified anyone about the delay.**" (Here "she" refers to the nurse)

Or:

"The doctor phoned the nurse because she was late **getting out of surgery and needed someone to check on her next patient.**" (Here "she" refers to the doctor)

The sentence structure makes it unclear which person "she" refers to, which is actually an interesting example of pronoun ambiguity in English!
