Parsha: Hayyei Sarah, "K'turah"

This came from another list:

This past Shabbat, totally out of the blue, a congregant came up to me and asked me a question. Apparently, I must have missed that class. I didn't know the answer. Forgive me as I post my ignorance, but as I do not have the answer, I turn to you...

When Sara hears that she will become pregnant, her response includes the fact that she says Abraham is old. She implies that he is not exactly the stallion he may have been in his younger years.

Much later on, we discover that Abraham has married Ketura and had more children. How did he do it?

---"Reuven"

Here are two approaches:

1. Both Abraham and Sara had a rebirth/rejuvenation (reJEWvenation?) when their names got changed because of the principle that a Convert is like a newborn [ger shinisgayer kekatan shenolad dami].
   
   
2. Ein mukdam um'uchar batorah. This story is out of sequence. It's just here as part of a flashback sequence to fill us in on the old news that Abraham had previously married another woman named Keturah.  It's placed right next to Abraham designating Isaac as his successor (excluding Isaac's half-siblings) before Abraham's own death.

Shalom,
RRW