Almost forzen turtle

I just found a hatchling dbt. in my outdoor pond setup! I haven’t had any terrapin in that cage since Sept. In November I found three baby terrapin in the outdoor pond, one was dead. The other two are doing great. They are already three inches. Two months after I moved all the terrapins out of the outdoor setup and in to a new indoor setup. Four out of five of the females laid nest. My question is, could the hatchling that I just found be from the same clutch as the turtle that I found in November? I know sometime hatchlings will wait until spring before coming out of the ground. Can half of the clutch come up, while the rest of the hatchlings stay under ground? I live in L.A. the couple of weeks have been really cold for us (highs in the fifties). The only reason that I think the turtle may have come out of the nest was that we have had a lot of rain. When I found it the water temperature in the pond was 47 degrees. I have been slowly raising his body temperature. The second day that I had him inside I thought he was going to die. He stopped more and when I picked him up his body was completely limp. When I found him, he did not have a egg sack, it looks like it might have been ripped off. Today is the third day that I have had him. After soaking him in some acriflavin yesterday he seems to be doing better. He is swimming around. I have not tried to feed him yet. Jonathan