How To Choose a Wet-Nurse:

I'm still a bit young, but apparently I have the makings of a good wet-nurse, particularly a "strong and big necke." Excellent. From Childbirth or The Happy Deliverie of Women by James Guillemeau, London 1612

Touching the Nurses person; for her age, she shall be chosen, when she is at her full growth; which is about five and twentie yeares of age, from which time, to the five and thirtieth yeare, is the age, wherein women are most temperate, healthfull, strong, and lusty: therefore one shall be chosen, that is betweene five and twentie, and five and thirtie yeares. Now, for her bodie, sho ought to be of a middle stature, neither too big, nor too little, nor too fat, nor too leane, nor yet too grosse, having good fleshy armes, and legges; and her flesh being hard and firm: she must not be deformed, neither squint-ey'd, lame, nor crump shouldred: she msut be one that is healthfull, and not subject to any disease: the complexion and colour of her bodie, must be lively, and rosie; she must not be spotted with rednesse, and especially she should not have red hair: and therefore, such as are of a browne complexion, are held to be best, whose haire is of a chest-nut colour, betweene yellow and blacke.
She must have a pleasing countenance, a bright and cleare eie, a well formed nose, neither crooked, nor of a bad smell, a ruddie mouth, and verie white teeth: She must deliver her words well, and distinctly, without stammering: and she must have strong and big necke: for thereby (as Hippocrates saith) may one judge, of the strength of the bodie. She must have a broad and large breast, garnished with two Paps of a reasonable bigness, neither limber, nor hanging down, but betweene hard and soft; full of Azure veines and Arteries, not being either knottie, of swolne bigger than they should be: the nipple which is in the midst of the breasts, ought to be somewhat eminent, and withall a ruddie colour like a Strawberie, it must be of a reasonable bignesse and thicknesse, and of a easie draught, that the child may take it the better, and sucke the easier.