Fate of Ellen Ryder

My theory. MomRyder died in a way not connected to the trilogy in any way. I think one dev mentioned a mystery behind it, probably a nice little short mission.

My crazy theory is that Ellen Ryder had a terminal illness, and the Ryder family joined the AI partially because it was agreed that Ellen could stay in stasis. The family hopes that amongst the flora and fauna, a cure for her rare condition may be found.

Doubt it will turn out to be true, but it would be WAY cooler than her just being arbitrarily dead. Great sidequest fodder.

I want mom to be estranged from her family. I want her to have protest the idea of building an AI and going to another galaxy (plus some other horrible thing dad did). It would cause so much drama for the twins if they were kept out of the loop So they went on thinking and believing in a series of events that weren't true.

Sort of the ME equivalent of Nora Fries, the wife of Mr Freeze?

Perhaps that's why Ellen and Alec began illegally researching AI, as a means to try to find a cure for her condition. An AI after all would be far easily able to process medical data and run simulations far faster than any human doctor could

Her health could have taken a turn for the worse, before they were able to get SAM fully operational, forcing her to enter into stasis. Alec responded by throwing himself into his work, which raised suspicion in the Alliance and lead him to get caught.