Perhaps seen in the corner of an uneasy smile or heard in the suddenly held breath…

tremulous (trem·u·lous): / TREM yuh luhs /
adjective

(1) characterized by trembling, quivering, or shaking, as in from fear or nervousness
(2) fearful or hesitant; timid; nervous; timorous
(3) vibratory or shaky, especially as is or might be caused by nervousness or weakness
(4) done with a trembling hand (with regards to writing)
(5) easily disordered, shaken, or disturbed; exceedingly or overly sensitive

[From Latin tremulus meaning “quivering, shaking,” from tremere meaning “to tremble.”]

Usage: Before his eyes rested upon my tremulous form, my thoughts turned within great circles of nervous intent, each radius drawn from my wish to flee, to scream in fright, to vanish in shadows deep, and to run to him with hope he might embrace me.