I am no breeder, and don’t intend her to have any more pups. so it just so happened that you decided now was a good time to let your 3.5 year old dog have puppies, right about the time when you can sell them for £2k a piece and upwards. And presumably if you already have homes for these puppies these buyers will know that the mother isn’t KC registered? Nope, didn’t think so.
I totally get that some people want their dogs to have puppies, and i also totally get that people are annoyed by the rescue process which IMO is a topic for a different discussion.
But the fact here is that anyone deciding to breed on a wim at a time when puppies have doubled in price is never going to look like anything other than a backyard breeder in it for the money only.
I know of at least three people over the past month who had planned to get a puppy and who have ended up finding out the hard way that most people who let their dogs have puppies are in it for the money.
One realised on her way to fetch the puppy it was a scam so didn’t proceed, she went to the local police station instead,
The other did get a puppy and it was ill within a day costing £8000 in vet bills and it didn’t survive.
Another one started to have second thoughts off the back of what she’d heard about the others, so decided not to go ahead, she rang the “breeder” who said that she should be quick, he only had one left.... She left it and rang him about a week later not telling him it was her, and he said that yes, if she came soon he only had one left.... 
Oh and, you know all those puppies who were seized in Gloucestershire? I know of someone who rehomed one of them after they’d been passed by the vet, and still that puppy has had multiple health problems.
Of course there are some who let their dogs have puppies and there turn out to be no issues with them. It’s precisely because of that fact that people still buy puppies off gumtree, and Pets4Homes etc, but it’s also what inspires others to do the same with only the money in mind.