Most women are not comfortable when having to use a "unisex" fitting pack.
There is no reason that you have to make do, as many brands make packs designed to closely fit the female form.
At BAC Outdoor you can find women's specific fit packs from Gregory, Lowe Alpine, Rab and deuter
 
In 1984, for maximum air circulation, dEUTER invented and patented the first mesh back system worldwide.
Then in 2006 they developed their SL range with women designers, testers, and together with high-altitude mountaineer Gerlinde Kaltenbrunner, they specifically produced a range of packs to suit the female anatomy.
 
Their SL (Slim LIne) Women's fit:
Your perfect backpack should not only be tailored to you in terms of capacity, but also fit.
Do you have a slim build and long legs?
dEUTER women's SL models are tailored to women's physiques.
The size of their women’s packs is characterized by a:
shorter back, narrower shoulder straps and a conical hip belt.

The SL shoulder straps have a pronounced S-shape and soft edges all around.
In addition, the ends of the straps are narrow.
For a perfect shoulder fit, nothing should pinch or rub.
Straps designed close together are tailored to narrower female shoulders.
The closed SL hip belts form a cone to perfectly match the shape of the female anatomy.
This conical shape is created by the buckles that connect towards the top and the anatomically conforming design of the SL hip belts.
The belts naturally hug the female hips.

(Because not everyone conforms to the norm, women's models may fit certain men well, and men's models can be comfortable for some women to wear)

See our range of Women's pack: HERE