Here are a few natural ways to continue that sentence, depending on the intended meaning:

**If "she" refers to the nurse:**
- "The doctor phoned the nurse because she was late **for her shift and patients were already waiting in the examination room.**"
- "The doctor phoned the nurse because she was late **and hadn't called in to explain her absence.**"

**If "she" refers to the doctor:**
- "The doctor phoned the nurse because she was late **and needed someone to inform the waiting patients about the delay.**"
- "The doctor phoned the nurse because she was late **leaving home and wanted to reschedule the morning appointments.**"

**A neutral continuation:**
- "The doctor phoned the nurse because she was late, **and together they worked out a plan to catch up on the day's appointments.**"

Note: The original sentence is actually ambiguous — "she" could grammatically refer to either the doctor or the nurse. Would you like me to continue it in a specific direction?
