So you're looking for a pack aimed at female stature? Well most civilian packs these days are adjustable or come in varying sizes.. That's basically the only difference between male and female packs, back size! Military packs are generally not adjustable and for a long time they had only one size. These days they're made in small, medium, large (generally).
If you're looking for a smaller pack, look for around 40-50L I would say. Big enough for essentials and maybe a bit extra, small enough for little day hikes and walking around town (while you perhaps leave the heavier things elsewhere?)
I love Berghaus, and spent a good two years with one of their 100L packs hitching around Europe. No complaints. I only use military packs, though. Generally a lot more durable, color schemes help blending in, and while they are generally heavier they use better materials for the rough way I am traveling about. Can't say i'm so knowledgeable with brand names, though. Google is great for many differing opinions.
I dislike too many zippers (they break = you're fucked, especially if they run down the length of the pack!), and too many pockets. Mine has a massive central bag with two side pouches that detach, as well as a couple lid pockets. I just divide my gear up into seperate bags and pull 'em out when needed. If I have/want to, I can take stuff out to carry wood/stones/whatever if needed.
Some packs are waterproof, but many come with built in rain covers or you can buy one for cheap (and they are light as hell). Not such an issue.
The simpler the better, really. But don't skimp on the webbing (straps, hip pads, etc), because if that is uncomfortable you're going to be hurrrrrtin'