In talking about Jane Austen's babyhood, Tomalin discusses how the Austen's kept their infants at home for a few months and then sent them out to a wet nurse, only to be visited occasionally until they returned at about 18 months to two years old. This was not unusual for the time and class, but Tomalin uses this to speculate that it may have created a barrier between Austen and her mother that time never really altered.
In Jane's case, the emotional distance between child and mother is obvious throughout her life...the most striking aspect of Jane's adult letters is their defensiveness. They lack tenderness towards herself as much as towards others. You are aware of the inner creature, deeply responsive and alive, but mostly you are faced with the hard shell; and sometimes a claw is put out, and a sharp nip is given to whatever offends. They are the letters of someone who does not open her heart; and in the adult who avoids intimacy you sense the child who was uncertain where to expect love or to look for security, and armoured herself against rejection. p.48
I think this is an astute observation--it seems that Austen's image has swung wildly between that saintly creature her family described after her death and a rather caustic wit. While some may describe Tomalin's analysis as psychobabble, I like the image of Austen as a tender soul housed in a hard shell, armed with a claws and teeth, and not afraid to use them when she feels she must.