First-time mother syndrome

I'm looking for more anecdotal evidence (or even better, actual scientific studies) concerning the poor survival rate of eggs from young females.

According to Caudata Culture Articles - Why Larvae Die, one of the causes of larvae death is "Maternal age – In some species, the first few batches of eggs produced by a young female are inferior. The eggs may be smaller than normal, and the eggs and early larvae may be difficult to raise and experience high mortality."

I've been told by a few experience breeders that indeed, this is a phenomena in axolotls.

So, what I want to know is what causes it and can be done about it? Is it is sufficient to let the mother get older, or does she actually need to lay some eggs? (I would think it would be enough to let her go through some cycles of egg re absorption, but then I would have thought that this would not happen in the first place for evolutionary reasons. So my logic is suspect.)

Needless to say, I am wondering because I have a first-time mother whose hatchlings are showing much higher mortality than expected. And people I sent eggs to are also seeing that same higher mortality, so it isn't just something I'm doing wrong here. They hatched well and started eating, but some stop eating, show signs of stress (curled tail at end), and eventually die.

I'm also considering that some sort of bacterial or viral infection somehow affected this batch of eggs - is that at all likely?

It would be good to know. I am a first time axie grandma and found that a lot more eggs never developed than o though would. I still have about 300 babies but I have 2 containers full of eggs (probably about 150) that just never formed. My female is about a year and a half. Although I also found that she probably load closer to 500 eggs on her first go so...

I have a clutch of eggs that I didn't sell because I was nervous about this. She's just a year now, and it's her first clutch. Of the approx 125 I saved, they all seem to be developing, although somewhat slower than my Leucy mom's have (although she's also several inches bigger, so maybe that matters).
Also, my female leucy had a near perfect success rate in her first clutch, which was not at all what I was expecting, so I hatched 100, expecting only 25-50% to hatch. Boy was I surprised I only lost 2!

And ... now I get to gather another data point, since my juvenile maybe-female turned out to be definitely female ... I should have gotten her out of that tank sooner, since the other two were definitely male. Oh well.

I suppose congratulations are in order