I'd be utterly amazed if Elaine can get pregnant. At her age she's almost certainly post-menopausal. Which is not a bad thing, you can freely creampie her without worrying about kids. cough
This is a good excuse to speculate wildly about the ages of the characters.
The first thing we know is that the MC was 4 when Becca left, and it's been roughly 20 years.
We know that Maddie and Lucy are roughly the same age and that Alice is younger than both of them.
We know that Sandy's first word was "Lu", meaning she's about 1.5 years older than Lucy at most.
We know that it took 3 years for Becca to get together with Christian (or maybe to give birth to Sandy? it's a little unclear who Mary's talking about in that scene).
We know that it's been ~3 years since Yvonne and Sandy saw each other (and they went to school together).
We know that all characters are > 18.
We know that Maddie had to repeat her last year of school.
We know that Becca had the MC pretty young (from the "teenage pregnancy" line).
By my esitmations, this puts Maddie ~= Lucy = 19
Alice = 18-19
Sandy ~= Yvonne = 21-22
MC ~= 27-29
Becca ~ early-mid 40s
Mary ~ early 40s
Which gives us a decent youngest possible for Elaine to be in her early 60s, so she's unlikely to still be fertile, but who knows with this family's genetics and the MC's magic dick (I'm not unconvinced that this family has some kind of supernatural powers as a rule).