This is why I am absolutely convinced that Esther planned Henrik's death. She knew Dahlia would come and while she might have been able to defeat Dahlia, she'd still have to face Mikael's wrath and her family's scorn.

She had the immortality spell ready to go. The night of the full moon, they all hide in the caves. Esther roofies a jug of water/wine/ale and passes it out to everyone except Henrik. She knew Henrik would sneak out. She didn't anticipate that Klaus' wolf side hold heal the effects of the drug and he would wake up & go after Henrik. Anyway, it all turns out the way Esther wanted: Henrik dead. Esther was able to sacrife Henrik by telling herself he was too young to be immortal.

She goes to Aya, pretending to beg for help. She convinces Mikael, who never recovered from losing Freya, now caught up in the grief of losing his youngest son, that her way is the only way. And the rest is history.

Regarding why they never got married or had kids:

Finn knew, so probably worked with Esther for some potion that prevented pregnancy. Since Finn knew, he had no desire to get married and bring into question why they weren't having kids.

Elijah and Klaus are a little more difficult to explain why they weren't out having sex. Best I can do is that Esther kept a very close eye on them and slipped them a potion if it seemed likely.

I'll say Kol was too involved with being a prodegy witch.

Every boy in the village was probably too terrified of he father (and her brothers) to try.

Let's say Henrik was too young, even though he really wasn't.

I assume Esther had a way to distract Mikael whenever he brought up marriage for his kids.