Here are some examples:
Erica turned to him
Erica turned towards him
Erica turned to face him
Erica turned to look at him
I'm not sure if the first one is grammatically incorrect and/or ambiguous?
All are grammatical. The first however, can have a different meaning. While the last three examples all indicate a physical movement, the first can be more metaphorical. To turn to someone means to ask them for help.
I couldn't understand the sentence, so I turned to ELU.
The previous sentence means that I asked ELU for help. The following sentence means that I physically turned my body
I turned my face to the wall.
All of those are equally correct grammatically, and all of them are in common usage.
Erica turned to Adam and asked, "why did I turn to face you?"