As Strumming Fool stated, as you go to a smaller body size, you generally lose some volume. So, there are a few things to consider. What kind of music do you play and in what type of venue. The other thing is how you play (strumming vs. flat-picking vs. fingerstyle). All these will help you decide on the size of guitar that best meets your needs (along with woods).
That being said, if you primarily play at home, then comfort while playing on the couch, etc., plays a more significant role. I can see how you love the GS mini for comfort, as I love them for that too. As you can tell from my screen name, I'm a woman too, but am fairly tall (5'9"), so I also find the GA (414) comfortable to play. But, I play in different settings and need the volume the 414 (and K24ce) offers. I also have a GC (512ce), which is very comfortable for my fingerstyle. I do recognize that I give up some volume, but, there are times that that guitar is what fits-the-bill.
So, to try to answer your questions, yes, I find the GS mini and the GC's very comfortable to play. There's really nothing you can do to make the 414 more comfortable, other than using light strings and making sure it is set-up well, for your playing style.
Hope this all make sense.