Sorry, that's not Jenny.

Mazus reptans?

The top picture is Creeping Jenny. 2 and 3 are not.

agree first pic is.. rest arent ..

CJ thrived wildly along my irrigation lines.. cover ten square feet from our little start in a season or two..

your soil is VERY VERY dry ... if it was like this last year .. with a new not established plant.. then your plant failed for lack of water ... as apparently CJ really liked my water ...

im sure your friend has more.. get a few more pieces.. and plant them now.. so they have fall and next spring.. before your soil gets dry in the heat of summer ...

and dont let your new weeds go to seed ... trust me on that ..

a good layer of mulch will reduce your weed production.. and help your favored plants get thru the heat of summer ...

ken

Given the large patch of seedlings I would look around for the parent plant in the vicinity.

The post says the first pic is an example of the CJ from last year.

I've grown Lysimachia nummularia in full day sun and it became agressive and stitched,(rooted) itself into nearby perennials. It's difficult to remove from other plants. It's not as agressive in deeper shade usually, but it can invade forest ecosystems and become a monoculture ground cover. I see it thriving in nearby preserves and it can handle being submerged by water for long periods of time. It's too troublesome to be a garden plant imo.