I encountered this issue when writing a fan fiction about a female character who became pregnant during the story. She asked a male friend to make her a shoulder holster. That's all that seemed to make sense, anatomically.

But she was living in a jungle and wore her gun (a five-inch barrelled M&P S&W .38) openly. A J-frame is much better for city use, and if someone still makes the Berns-Martin system or something similar, that might be the answer.

I did ask several women, but none had ever carried a gun. Still, after thinking it over, they told me that a shoulder rig sounded good.

My character actually had more trouble figuring out how to carry spare ammo for her rifle. She figured that a bandolier might work, if it didn't abrade her tender frontal appendages. If anyone cares, one rifle was a Mannlicher-Schoenauer 6.5mm and the other, a Winchester M-92 .44/40. The story was set in Brazil in the 1920's, in case the gun choices seem archaic.

Keep in mind that in a city setting, the covering garment must not expose the gun, and a coat often gapes enough to reveal a shoulder holster. A shoulder bag might be the best bet, if a trifle slow to get at.

Good luck to you and your lady. I hope that all goes well with the pregnancy. Been there; done that, twice. Or, my ex-wife did.