Full and Hardness around Nipples

Question
I have an approximate 6 month stray I took in who gave birth on 7-8.  6 of her nipples seem to be in use (I have never seen the litter so don't know the size) and w/in the last 48 hours the area immediately around each nipple is swelling and seems to be firming up.  Is this a process she is going through to set her up for stopping milk production.  Along with the dry cat food I feed her she eats rodents she catches including mice, rabbbits and chipmunks.
Thank you.

Answer
Monti,

Most kittens are weaned around 4-6 weeks of age, so it is probable that her milk is "packing up".  She will harden around the nipples for a while and, in a couple of weeks, her body will absorb any of the dried up milk.

Best regards... Norm.