I have a Shield, a 3953 and a 3953TSW. The TSW is a pre-rail 7 shot mag so it's slightly shorter, but I have some old metal bottom 7 shot 3953 mags that make the non-TSW just as short, but they don't feel as good as the plastic flat or curved bottom 8 rd mags. I personally love the S&W DAO action and carry the 3953's when I can since they are flat, ultra reliable and feel like a more substantial fighting pistol. That said, my Shield has been 100% reliable and is more lighter/concealable IMO. I just haven't acquired a proper IWB holster for the Shield yet.
I'm not a huge fan of striker fired guns having started shooting in what was then pretty much a revolver/1911/Hi-Power only world and 9mm ammo was relatively expensive and very hard to find around here (Super Vel was the only HP ammo for 9mm at 1 time). So my personal preference for a visible hammer and metal frame may not translate to someone who was weaned on polymer frames with striker mechanisms. Some complain about the safety on the Shield, but in a purse holster or some other carries, depending on her comfort level, I like having that option if she practices disengaging it when ready to fire. They now make a Shield without the safety, but it is small and is not a problem IMO. That said, my daughter has my Shield and other emergency supplies in a MOAB 6 in her car from her paranoid father. YMMV