The 'daughter plants' as you called them, are the little plantlets that hang down from a stalk from the main plant. Just stick them in some soil under the leaves, leave them attached to the main plant untill then root then snip them off.

Myron's advice is exactly right, and you will get fruit next year from both. The 'mother' plants only last about 3 years, so it's always good to save the 'offspring'!

I think the problem is that these are in the ground and the runners have rooted there and Jrh can't tell which are the younger ones?

Can you see where your original rows were? If so any plants that aren't in the rows will be younger ones. This years plants will probably still have the runner stems attached if you can find them. Some growers have more than one strawberry bed. They plant out the current years plants in a second bed and plantlets from that the following year in third. After the first bed has been producing for three years it is cleared and the cycle begins again with that bed taking the new plants from the third one. If you haven't got room to do that at least you can see the idea behind it.