I understand a very limited number of the issues a woman has to deal with in carrying (my lack of knowledge, not a slight). What I can offer is that what you see as printing or a tell may be a result of many new CCW or LE's over reaction about a 'print'.
Your 642 should be good in a tight OWB holster with a good belt, carried at the 230 or 330 position. If it doesnt dont work there, try a cross draw on the off side. I have no experience with the G27.
Work with two layers of tops. A soft smooth undergarment is a must between you and the weapon, with a medium weight cover garment.
Keep in mind that most of the public would not notice if you carried a bread box on your right hip.
I frequently carry a full size 1911 in a Hume speed scabbard OWB that hangs an inch below my shirt or jacket. No one notices more than me.