My feral cat has brought yet more kittens

[oyster]

I have two surviving ferals in my yard. They have been with me over 8 years or so. They arrive punctually for their food, and when needed, sleep in their spaces which are winterized. They are both neutered which I did with TNR but I guess the one girl wasn't done properly because she still goes into heat and can lactate (a fact I found out about when she stole a 2 week old kitten in Spring).
This feral has a habit of bringing or stealing kittens from other cat moms in the area, and bringing them over to me. She has brought over 7 kittens in the last 3 years, all of whom I have trapped and rehomed through our local shelter.
Today, she brought 2 more! Thankfully, they are walking and running, as well as eating solids so I am keeping an eye on them. I will feed them all regularly and try to trap and rehome, as usual. However, the experienced lady at the shelter thinks it might be better for the "mom" to keep them this time and it might cure her of her habit of bringing these kittens.
Do you think that might work if I leave them alone? I worry because we already have a lot of feral cats in the area thanks to a large farmhouse near our home. The farmer likes to keep them for catching mice but doesn't take care of them in any way.
Also, one of my feral cats might get turfed out if the younger cats take over our yard. And I definitely do not want that.
Any suggestions?

 

[Kris107]

I lean towards doing what you've been doing - getting them fixed and adopted. An outdoor cat's life is harder. If the pseudo/kidnap mom wasn't fixed correctly, then she may always get this drive. She's bringing the babies to you to help care for them and she trusts you. I can't imagine that she wouldn't keep doing that. IF you leave them, make sure you fix them sooner rather than later in case one runs off. They can be done after they're 2 lbs.

 

[fionasmom]

I don't see where letting her keep the new kittens would have any effect. While cats may remain friendly with offspring or siblings as they grow up, they don't see it as humans would in the sense of "I have all the kids I can handle." Since she was spayed incorrectly, I don't see whatever hormonal response she is having stopping. This must be frustrating, but I would continue to do what you have been doing.

 

[oyster]

Thank you for your responses. I found a local foster cat mom and she urged me to rescue the two kittens as there is highly contagious FIP going around. So, I have set the trap and will wait a few days for them to be used to it. The weather is also horrible so I can't lure them into the trap with food as the rain and wind will just toss it about.
The good thing is that the kittens are very used to me and have started coming closer and closer.