the full line is "I have given suck, and know How tender 'tis to love the babe that milks me"
Which would certainly seem to imply that they have children that she has breastfed and knows the love of a suckling baby. but it is also pretty clear from the rest of the play that they have no children. (Macbeth will be king but Banquo's descendants will rule)
"I have given suck, and know
How tender 'tis to love the babe that milks me:
I would, while it was smiling in my face,
Have pluck'd my nipple from his boneless gums,
And dash'd the brains out, had I so sworn as you
Have done to this."
While you are here JJ, your Fantasy Team sucks as well ! Get over to the site and use your Transfer Button to take out the duffers as you holding us all up at present with -3 ! lol