Starting with my own personal bias: if legal or economic circumstances ever limited me to one gun, it would be my Glock 26. It is the standard in size efficiency by which all other guns should be judged, and the accuracy and ease of shooting compares to (and sometimes exceeds) that of full-sized guns. Holster and accessory availability are among the highest for any gun.
The Beretta .380 is big and bulky for a .380. It has been touted as an excellent choice for those with weak hands, with the tip-up barrel and (if I understand correctly) the ability to safely carry it with the hammer down, or with the hammer cocked and the thumb safety on safe. Unless this is an issue for your wife or son, I doubt this gun would be the best choice.
The larger Glock 19 has been called an excellent choice for ladies due to the easy trigger pull and relatively easy slide manipulation. The grip is big enough to get 3 fingers on it, and this helps. The next Glock I buy will either be a 19 or a 32. Maybe this size Glock is worth considering?
It looks like a lot of this will depend on what your wife and son like, so ask them what they think. Find our their likes and dislikes, and find out why they like or don't like what they do. Look for patterns. This will better enable you to make your choice.
If they like the G26, then you probably want more than one.
