New Kitten suckling on my adolencent Cat HELP please

I just got a new kitten named Jack a few days ago. I have my older girls of in which have never had a litter and are not fixed yet. I started noticing their loving behavior towards Jack and his sister whom I was cat sitting temporarily. The older girls have been teaching Jack how to climb and groom. But today there was some odd behavior coming from Jack and one of my girls. Teia is laying in my laundry basket comfortably and is allowing Jack to suckle on her as if she is momma. She is even going as far to groom him in the process. I am concerned of this behavior because 1) Teia is allowing it and 2) Jack is a new kitten to the home and was already weened from his mother. He still is eating hard food. Is their any chance that Teia will start producing milk due to the stimulation???? Can someone help me please?

I wouldn't be concerned, it's actually quite sweet!  I can't tell you if your female cat will produce milk from the sucking, but I do know that cats who have been spayed when pregnant can still produce milk in response to sucking.  It's a wonderful bonding experience for both and I see no reason to separate them and try to prevent it although it might be wise to get her spayed NOW, because if she does produce milk, then you can't get her spayed until the milk goes away, and obviously he can't be sucking on her while she's healing from a spay, so do it before he gets in the habit.  If he does it after she's healed, then no problem.  Even if he's nursing, he will continue to eat hard food (and he should be given wet food as well, check out our Nutrition threads regarding this, an all dry food diet is not good for them in the long run.)   I had one Siamese kitten who started sucking on a tuft of hair from an older neutered male, and he ended up doing that his whole life.  The two became very bonded, and it was just a comfort thing.  In my work with rescue moms and babies, many of the babies still nurse for comfort when their moms let them, and some do, and some don't, they just rabbit kick the babies away.  Mostly they just do it at "bedtime" for comfort, just like babies like to have bottles at bedtime even if they eat solid food during the day.

Considering he is still a little kitten, I wouldn't be concerned. He's still in the habit of suckling like my cat when she was a kitten. It's very nice how Teia is allowing him, it's just showing a very good bonding between the two. I doubt she will end up producing milk, sooner or later Jack will get out of the habit, like most kittens. 

Thanks for the advice. I do plan on getting them spayed and little jack neutered. I have a few other financial responsibilities first. I was recently in a rather horrid custody battle. But i would like to share that ive noticed my older cats taking parenting roles. Teia is like mommy and mella-rue is like daddy. Mella-rue is attempting to teach jack how to climb my small indoor palm tree. And teia is his pillow and cuddle bug. Thanks for the advice. this is a pic i took a second ago. Hes rooting and she's welcoming and cuddling him.