Ah no, she is very strong physically as well.
In the first movie, Miroku attempts to carry the Hiraikotsu, and complains that it is heavy.
Sango never complains about it. xD (Well duh, she's used to carrying it, but..)
I bet she is up-to-par with Miroku's physical strength, or even stronger.
After all Miroku relies on spiritual power and not physical power.
So Sango is indeed emotionally and physically strong.