her way to work. She is driving to work.
This
means: she is driving now, at the time of speaking. The action is not finished.AM/IS/Are + ING is the present continuous.
I AM (=I’m)
He/She/It IS
We/You/They ARE
I am doing smth = I’m in the middle of doing it; I’ve started doing it and haven’t finished:
Please don’t make so much noise. I’m trying to work. (not I try)
Where is Mark? He is having shower. (not He has a shower)